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1. Understanding Electromagnetic Interactions and Electron Transfer in Ga Nanoparticle–Graphene–Metal Substrate Sandwich Systems

Author

Yael Gutiérrez, Maria M. Giangregorio, April S. Brown, Fernando Moreno, and Maria Losurdo

Subjects
graphene, gallium nanoparticles, plasmonics, copper, nickel, Technology, Engineering (General). Civil engineering (General), TA1-2040, Biology (General), QH301-705.5, Physics, QC1-999, Chemistry, QD1-999
Abstract

Plasmonic metal nanoparticle (NP)−graphene (G) systems are of great interest due their potential role in applications as surface-enhanced spectroscopies, enhanced photodetection, and photocatalysis. Most of these studies have been performed using noble metal NPs of silver and gold. However, recent studies have demonstrated that the noble metal−graphene interaction leads to strong distortions of the graphene sheet. In order to overcome this issue, we propose the use of Ga NPs that, due to their weak interaction with graphene, do not produce any deformation of the graphene layers. Here, we analyze systems consisting of Ga NP/G/metal sandwich coupling structures, with the metal substrate being, specifically, copper (Cu) and nickel (Ni), i.e., Ga NP/G/Cu and Ga NPs/G/Ni. We experimentally show through real-time plasmonic spectroscopic ellipsometry and Raman spectroscopy measurements of the quenching of the Ga NP localized surface plasmon resonance (LSPR) depending on the wetting of the graphene by the Ga NPs and on the electron transfer through graphene. Theoretical finite-difference time-domain (FDTD) simulations supportively demonstrate that the LSPR in such sandwich structures strongly depends on the contact angle of the NP with graphene. Finally, we also provide evidence of the electron transfer from the Ga NPs into the graphene and into the metal substrate according to the work function alignments. These considerations about the contact angle and, consequently, geometry and wetting of the metal NPs on graphene, are useful to guide the design of those plasmonic systems to maximize electromagnetic enhancement.

Published
2019
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2. Characterization of MBE-grown InAlN/GaN heterostructure valence band offsets with varying In composition

Author

Wenyuan Jiao, Wei Kong, Jincheng Li, Kristen Collar, Tong-Ho Kim, Maria Losurdo, and April S. Brown

Subjects
Physics, QC1-999
Abstract

Angle-resolved X-ray photoelectron spectroscopy (XPS) is used in this work to experimentally determine the valence band offsets of molecular beam epitaxy (MBE)-grown InAlN/GaN heterostructures with varying indium composition. We find that the internal electric field resulting from polarization must be taken into account when analyzing the XPS data. Valence band offsets of 0.12 eV for In0.18Al0.82N, 0.15 eV for In0.17Al0.83N, and 0.23 eV for In0.098Al0.902N with GaN are obtained. The results show that a compositional-depended bowing parameter is needed in order to estimate the valence band energies of InAlN as a function of composition in relation to those of the binary endpoints, AlN and InN.

Published
2016
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3. GaAs1−yBiy Raman signatures: illuminating relationships between the electrical and optical properties of GaAs1−yBiy and Bi incorporation

Author

Jincheng Li, Kamran Forghani, Yingxin Guan, Wenyuan Jiao, Wei Kong, Kristen Collar, Tong-Ho Kim, Thomas F. Kuech, and April S. Brown

Subjects
Physics, QC1-999
Abstract

We report the use of two Raman signatures, the Bi-induced longitudinal-optical-plasmon-coupled (LOPC) mode and the GaAs Fröhlich scattering intensity, present in nominally undoped (100) GaAs1−yBiy to predict the 300K photoluminescence intensity and Bi composition (y) in GaAs1−yBiy. The LOPC mode is used to calculate the hole concentration in GaAs1−yBiy epitaxial layers. A linear relationship between hole concentration and photoluminescence intensity is found for a range of samples grown at various temperatures and growth rates. In addition, the composition (y) of Bi in GaAs1−yBiy is also found to be linearly related to the GaAs Fröhlich scattering intensity.

Published
2015
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5. Sustainable and Tunable Mg/MgO Plasmon-Catalytic Platform for the Grand Challenge of SF6 Environmental Remediation

Author

Maria M. Giangregorio, Maria Losurdo, April S. Brown, Francisco González, Fabio Palumbo, Fernando Moreno, and Yael Gutiérrez

Subjects
Waste management, Environmental remediation, Magnesium, Mechanical Engineering, chemistry.chemical_element, Bioengineering, 02 engineering and technology, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Catalysis, Sulfur hexafluoride, chemistry.chemical_compound, chemistry, Greenhouse gas, Environmental science, General Materials Science, 0210 nano-technology, Plasmon
Abstract

Sulfur hexafluoride (SF6) is one of the most harmful greenhouse gases producing environmental risks. Therefore, developing ways of degrading SF6 without forming hazard products is increasingly impo...

Published
2020

7. Gallium Plasmonic Nanoantennas Unveiling Multiple Kinetics of Hydrogen Sensing, Storage, and Spillover

Author

Maria Losurdo, Maria M. Giangregorio, Alexandra Suvorova, Sergey Rubanov, Yael Gutiérrez, April S. Brown, Fernando Moreno, and Universidad de Cantabria

Subjects
Materials science, Hydrogen, chemistry.chemical_element, Nanoparticle, Gallium, 02 engineering and technology, 010402 general chemistry, 7. Clean energy, 01 natural sciences, Hydrogen storage, Adsorption, Metal hydrides, General Materials Science, Photocatalysis, Plasmon, business.industry, Mechanical Engineering, 021001 nanoscience & nanotechnology, 0104 chemical sciences, chemistry, Mechanics of Materials, Plasmonics, Optoelectronics, Oxygen reverse spillover, Hydrogen spillover, 0210 nano-technology, business, Optical hydrogen sensing, Localized surface plasmon
Abstract

Hydrogen is the key element to accomplish a carbon-free based economy. Here, the first evidence of plasmonic gallium (Ga) nanoantennas is provided as nanoreactors supported on sapphire (α-Al2O3) acting as direct plasmon-enhanced photocatalyst for hydrogen sensing, storage, and spillover. The role of plasmon-catalyzed electron transfer between hydrogen and plasmonic Ga nanoparticle in the activation of those processes is highlighted, as opposed to conventional refractive index-change-based sensing. This study reveals that, while temperature selectively operates those various processes, longitudinal (LO-LSPR) and transverse (TO-LSPR) localized surface plasmon resonances of supported Ga nanoparticles open selectivity of localized reaction pathways at specific sites corresponding to the electromagnetic hot-spots. Specifically, the TO-LSPR couples light into the surface dissociative adsorption of hydrogen and formation of hydrides, whereas the LO-LSPR activates heterogeneous reactions at the interface with the support, that is, hydrogen spillover into α-Al2O3 and reverse-oxygen spillover from α-Al2O3. This Ga-based plasmon-catalytic platform expands the application of supported plasmon-catalysis to hydrogen technologies, including reversible fast hydrogen sensing in a timescale of a few seconds with a limit of detection as low as 5 ppm and in a broad temperature range from room-temperature up to 600 °C while remaining stable and reusable over an extended period of time. The authors thank all of the students and colleagues in their groups who were actively involved with nanoparticles research. M.L., Y.G., and F.M. have received funding from the European Union's Horizon 2020 Research and Innovation Program under Grant Agreement No. 899598—PHEMTRONICS. F.M. acknowledges MINECO (Spanish Ministry of Economy and Competitiveness, project PGC2018-096649-B-100).

Published
2021

8. No correlation between Solar flares and the decay rate of several β-decaying isotopes

Author

Marc Schumann, J.C.P.Y. Nobelen, April S. Brown, R. Perci, C. Reuter, Laura Baudis, J. R. Angevaare, R. F. Lang, A. Massafferri, A. P. Colijn, P. A. Breur, University of Zurich, and Breur, P A

Subjects
Physics, Solar flare, Isotope, 530 Physics, 010308 nuclear & particles physics, Astronomy and Astrophysics, 10192 Physics Institute, Astrophysics, 01 natural sciences, Lower limit, Astrophysics - Solar and Stellar Astrophysics, 0103 physical sciences, 3103 Astronomy and Astrophysics, Neutrino, Nuclear Experiment, 010303 astronomy & astrophysics
Abstract

We report on finding no correlation between the two strongest observed Solar flares in September 2017 and the decay rates of $^{60}$Co, $^{44}$Ti and $^{137}$Cs sources, which are continuously measured by two independent NaI(Tl) detector setups. We test for variations in the number of observed counts with respect to the number of expected counts over multiple periods with timescales varying from 1 to 109 hours around the Solar flare. No excess or deficit exceeds the 2$\sigma$ global significance. We set a conservative lower limit on the decay rate deviation over an 84-hour period around the two correlated Solar flares in September 2017 to $0.044\%$ with 2$\sigma$ confidence. A fractional change of $~0.1\%$ in the decay rate of $^{54}$Mn over a period of 84 hours was claimed with 7$\sigma$ significance during multiple Solar flares in December 2006. We exclude such an effect at 4.7$\sigma$ significance., Comment: Corrected typos, revised table values, results unchanged Will be published in Astroparticle Physics, Volume 103, December 2018, Pages 62-66 9 pages, 2 figures and 1 table. Keywords: Solar Flares, Radioactivity, Beta Decays, Neutrinos, Global Significance

Published
2018

9. Search for inelastic scattering of WIMP dark matter in XENON1T

Author

A. Manfredini, L. Scotto Lavina, Hardy Simgen, A. D. Ferella, R. Budnik, Yuehuan Wei, L. Grandi, G. Koltman, C. Weinheimer, K. Martens, F. Arneodo, M. Messina, Lorne Levinson, F. Joerg, Kaixuan Ni, D. Cichon, N. Kato, C. Macolino, L. Hoetzsch, A. Elykov, T. Wolf, Elena Aprile, João Cardoso, M. Pierre, D. Ramírez García, F. Gao, Keita Mizukoshi, P. Shagin, J. A. M. Lopes, Y. Mosbacher, Y. Ma, Masaki Yamashita, P. Di Gangi, S. Moriyama, T. Zhu, F. D. Amaro, Guillaume Plante, Fabrizio Marignetti, M. Vargas, H. Landsman, M. P. Decowski, April S. Brown, Boris Bauermeister, Jochen Schreiner, D. Masson, T. Marrodán Undagoitia, L. Bellagamba, A. Rocchetti, S. Liang, Manfred Lindner, L. Althueser, K. Odgers, J. Howlett, Katsuki Hiraide, F. Lombardi, M. Alfonsi, S. Andaloro, J.M.F. dos Santos, F. Agostini, R. Di Stefano, V. Pizzella, Giacomo Bruno, J. Naganoma, N. Šarčević, J. Qin, Sebastian Lindemann, G. Sartorelli, J. Pienaar, C. Capelli, N. Rupp, Gian Carlo Trinchero, K. Morå, Michelle Galloway, H. Schulze Eißing, E. Angelino, S. Bruenner, A. Molinario, S. Mastroianni, Jean-Pierre Cussonneau, M. Iacovacci, A. Di Giovanni, Bart Pelssers, C. Tunnell, C. Wittweg, J. P. Zopounidis, D. Coderre, Manuel Gameiro da Silva, M. Scheibelhut, Jelle Aalbers, A. Depoian, M. Selvi, D. Schulte, Kathrin Valerius, A. Kopec, S. Reichard, Qing Lin, J. Qi, J. Palacio, J. Ye, B. Cimmino, M. Clark, Atsushi Takeda, Shingo Kazama, G. Volta, Uwe Oberlack, V. C. Antochi, Ethan Brown, Kentaro Miuchi, C. Therreau, J. Cuenca, Y. Zhang, Julien Masbou, Z. Xu, M. Murra, W. Fulgione, Laura Manenti, C. Hils, Sara Diglio, J. Mahlstedt, G. Zavattini, Laura Baudis, P. Gaemers, F. Toschi, M. L. Benabderrahmane, J. Long, J. R. Angevaare, E. Shockley, Jan Conrad, Masanori Kobayashi, R. Gaior, Yoshitaka Itow, M. Weiss, D. Thers, Marc Schumann, F. Semeria, R. F. Lang, A. P. Colijn, D. Wenz, R. Peres, A. Mancuso, Aprile, E., Aalbers, J., Agostini, F., Alfonsi, M., Althueser, L., Amaro, F. D., Andaloro, S., Angelino, E., Angevaare, J. R., Antochi, V. C., Arneodo, F., Baudis, L., Bauermeister, B., Bellagamba, L., Benabderrahmane, M. L., Brown, A., Brown, E., Bruenner, S., Bruno, G., Budnik, R., Capelli, C., Cardoso, J. M. R., Cichon, D., Cimmino, B., Clark, M., Coderre, D., Colijn, A. P., Conrad, J., Cuenca, J., Cussonneau, J. P., Decowski, M. P., Depoian, A., Di Gangi, P., Di Giovanni, A., Di Stefano, R., Diglio, S., Elykov, A., Ferella, A. D., Fulgione, W., Gaemers, P., Gaior, R., Galloway, M., Gao, F., Grandi, L., Hils, C., Hiraide, K., Hoetzsch, L., Howlett, J., Iacovacci, M., Itow, Y., Joerg, F., Kato, N., Kazama, S., Kobayashi, M., Koltman, G., Kopec, A., Landsman, H., Lang, R. F., Levinson, L., Liang, S., Lin, Q., Lindemann, S., Lindner, M., Lombardi, F., Long, J., Lopes, J. A. M., Ma, Y., Macolino, C., Mahlstedt, J., Mancuso, A., Manenti, L., Manfredini, A., Marignetti, F., Marrodan Undagoitia, T., Martens, K., Masbou, J., Masson, D., Mastroianni, S., Messina, M., Miuchi, K., Mizukoshi, K., Molinario, A., Mora, K., Moriyama, S., Mosbacher, Y., Murra, M., Naganoma, J., Ni, K., Oberlack, U., Odgers, K., Palacio, J., Pelssers, B., Peres, R., Pienaar, J., Pierre, M., Pizzella, V., Plante, G., Qi, J., Qin, J., Ramirez Garcia, D., Reichard, S., Rocchetti, A., Rupp, N., Dos Santos, J. M. F., Sartorelli, G., Sarcevic, N., Scheibelhut, M., Schreiner, J., Schulte, D., Schulze Eissing, H., Schumann, M., Scotto Lavina, L., Selvi, M., Semeria, F., Shagin, P., Shockley, E., Silva, M., Simgen, H., Takeda, A., Therreau, C., Thers, D., Toschi, F., Trinchero, G., Tunnell, C., Valerius, K., Vargas, M., Volta, G., Wei, Y., Weinheimer, C., Weiss, M., Wenz, D., Wittweg, C., Wolf, T., Xu, Z., Yamashita, M., Ye, J., Zavattini, G., Zhang, Y., Zhu, T., Zopounidis, J. P., XENON Collaboration, Columbia University [New York], Oskar Klein Centre [Stockholm], Stockholm University, University of Bologna, Johannes Gutenberg - Universität Mainz (JGU), Westfälische Wilhelms-Universität Münster (WWU), University of Coimbra [Portugal] (UC), Università degli studi di Torino (UNITO), University of Amsterdam [Amsterdam] (UvA), Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), XENON, IoP (FNWI), and XENON (IHEF, IoP, FNWI)

Subjects
xenon: target, Photon, Physics::Instrumentation and Detectors, Parameter space, 01 natural sciences, WIMP: dark matter, High Energy Physics - Experiment, astro-ph.CO, High Energy Physics - Experiment (hep-ex), XENON, Recoil, WIMP, WIMP nucleus: cross section, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Dark Matter, parameter space, Nuclear Experiment, ComputingMilieux_MISCELLANEOUS, nucleus: recoil, Physics, Dark Matter, Inelastic scattering, XENON, Direct Dark Matter, photon, Astrophysics::Instrumentation and Methods for Astrophysics, Direct Dark Matter, Weakly interacting massive particles, signature, Astrophysics - Cosmology and Nongalactic Astrophysics, Particle physics, Inelastic scattering, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Dark matter, FOS: Physical sciences, WIMP: mass, Astrophysics::Cosmology and Extragalactic Astrophysics, NO, PE2_2, PE2_1, 0103 physical sciences, ddc:530, 010306 general physics, 010308 nuclear & particles physics, Scattering, WIMP nucleus: interaction, Dark, matter, WIMP: interaction, High Energy Physics::Experiment, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics and astroparticle physics, experimental results
Abstract

We report the results of a search for the inelastic scattering of weakly interacting massive particles (WIMPs) in the XENON1T dark matter experiment. Scattering off $^{129}$Xe is the most sensitive probe of inelastic WIMP interactions, with a signature of a 39.6 keV de-excitation photon detected simultaneously with the nuclear recoil. Using an exposure of 0.89 tonne-years, we find no evidence of inelastic WIMP scattering with a significance of more than 2$\sigma$. A profile-likelihood ratio analysis is used to set upper limits on the cross-section of WIMP-nucleus interactions. We exclude new parameter space for WIMPs heavier than 100 GeV/c${}^2$, with the strongest upper limit of $3.3 \times 10^{-39}$ cm${}^2$ for 130 GeV/c${}^2$ WIMPs at 90\% confidence level., Comment: 9 pages, 4 figures

Published
2021

10. Search for Coherent Elastic Scattering of Solar B8 Neutrinos in the XENON1T Dark Matter Experiment

Author

Y. Mosbacher, Y. Ma, D. Ramírez García, J. Pienaar, Jelle Aalbers, Kentaro Miuchi, C. Therreau, M. Messina, F. Joerg, C. Macolino, L. Hoetzsch, J. P. Zopounidis, R. Budnik, D. Wenz, Masahiro Yamashita, Yuehuan Wei, R. Peres, J. Howlett, C. Capelli, M. L. Benabderrahmane, Ethan Brown, K. Morå, P. Shagin, Laura Baudis, Atsushi Takeda, L. Grandi, G. Koltman, J. A. M. Lopes, C. Hils, N. Kato, A. Mancuso, E. Shockley, C. Wittweg, P. Gaemers, A. Manfredini, M. Alfonsi, D. Coderre, Katsuki Hiraide, J. Mahlstedt, G. Zavattini, F. Lombardi, S. Andaloro, F. Toschi, V. Pizzella, D. Cichon, Marc Schumann, L. Scotto Lavina, P. Di Gangi, M. Vargas, Hardy Simgen, R. Di Stefano, A. D. Ferella, Z. Xu, D. Schulte, J. Qin, W. Fulgione, R. Gaior, J. Naganoma, M. Murra, Kathrin Valerius, S. Bruenner, C. Weinheimer, Kaixuan Ni, João Cardoso, M. Pierre, N. Rupp, Shigetaka Moriyama, Yoshitaka Itow, Giacomo Bruno, T. Marrodán Undagoitia, F. Gao, J. Long, Laura Manenti, Michelle Galloway, Uwe Oberlack, Sara Diglio, M. Clark, Elena Aprile, B. Cimmino, T. Zhu, A. Elykov, T. Wolf, H. Landsman, Keita Mizukoshi, M. Weiss, D. Thers, Manuel Gameiro da Silva, F. D. Amaro, E. Angelino, S. Liang, F. Semeria, Guillaume Plante, R. F. Lang, Julien Masbou, A. Di Giovanni, Boris Bauermeister, G. Volta, Jean-Pierre Cussonneau, A. P. Colijn, Bart Pelssers, V. C. Antochi, M. P. Decowski, C. Tunnell, J.M.F. dos Santos, F. Arneodo, F. Agostini, K. Martens, Lorne Levinson, J. R. Angevaare, Fabrizio Marignetti, Manfred Lindner, J. Ye, L. Althueser, Sebastian Lindemann, L. Bellagamba, April S. Brown, G. Sartorelli, Gian Carlo Trinchero, S. Mastroianni, Jochen Schreiner, S. Ahmed Maouloud, J. Qi, J. Palacio, Shingo Kazama, A. Rocchetti, Jan Conrad, Masanori Kobayashi, D. Masson, S. Reichard, J. Cuenca, Y. Zhang, H. Schulze Eißing, A. Molinario, M. Iacovacci, A. Depoian, M. Selvi, A. Kopec, and K. Odgers

Subjects
Elastic scattering, Physics, Physics::Instrumentation and Detectors, Scattering, Astrophysics::High Energy Astrophysical Phenomena, Solar neutrino, Dark matter, General Physics and Astronomy, chemistry.chemical_element, 01 natural sciences, 7. Clean energy, Nuclear physics, Xenon, Recoil, chemistry, 0103 physical sciences, High Energy Physics::Experiment, Neutrino, Nuclear Experiment, 010306 general physics, Order of magnitude
Abstract

We report on a search for nuclear recoil signals from solar $^8$B neutrinos elastically scattering off xenon nuclei in XENON1T data, lowering the energy threshold from 2.6 keV to 1.6 keV. We develop a variety of novel techniques to limit the resulting increase in backgrounds near the threshold. No significant $^8$B neutrino-like excess is found in an exposure of 0.6 t $\times$ y. For the first time, we use the non-detection of solar neutrinos to constrain the light yield from 1-2 keV nuclear recoils in liquid xenon, as well as non-standard neutrino-quark interactions. Finally, we improve upon world-leading constraints on dark matter-nucleus interactions for dark matter masses between 3 GeV/c$^2$ and 11 GeV/c$^2$ by as much as an order of magnitude.

Published
2021

11. Projected WIMP sensitivity of the XENONnT dark matter experiment

Author

K. Martens, M. L. Benabderrahmane, Ethan Brown, N. Šarčević, A. Manfredini, G. Sartorelli, Laura Manenti, Gian Carlo Trinchero, K. Odgers, N. Kato, M. Vargas, T. Marrodán Undagoitia, A. Depoian, L. Grandi, G. Koltman, E. López Fune, A. Rocchetti, P. Shagin, C. Wittweg, J. A. M. Lopes, D. Coderre, F. Toschi, P. Di Gangi, C. Hils, M. Selvi, Manuel Gameiro da Silva, A. Molinario, M. Scheibelhut, J. Mahlstedt, G. Zavattini, M. P. Decowski, Manfred Lindner, Sara Diglio, M. Messina, L. Scotto Lavina, D. Cichon, Michelle Galloway, T. Berger, A. Kopec, Qing Lin, Kaixuan Ni, Hardy Simgen, F. Joerg, Jean-Pierre Cussonneau, A. D. Ferella, J. Long, N. Rupp, Bart Pelssers, Yuehuan Wei, Marc Schumann, W. Fulgione, Elena Aprile, A. Elykov, J. Ye, C. Tunnell, D. Schulte, E. Angelino, J.M.F. dos Santos, M. Iacovacci, April S. Brown, E. Shockley, Han Wang, Keita Mizukoshi, F. Agostini, Katsuki Hiraide, R. Di Stefano, Sebastian Lindemann, Jochen Schreiner, L. Althueser, A. Di Giovanni, J. P. Zopounidis, S. Reichard, Z. Xu, H. Landsman, G. Eurin, L. Levinson, D. Ramírez García, Atsushi Takeda, D. Masson, C. Hasterok, S. Bruenner, S. Mastroianni, J. Pienaar, Yanxi Zhang, Laura Baudis, D. Wenz, R. Peres, F. Arneodo, M. Clark, Auke-Pieter Colijn, D. Barge, João Cardoso, Giacomo Bruno, F. Gao, B. Cimmino, Kathrin Valerius, J. Qin, R. Gaior, A. Mancuso, Ran Budnik, Yoshitaka Itow, Uwe Oberlack, G. Volta, Ch. Weinheimer, Jelle Aalbers, C. Macolino, L. Hoetzsch, Y. Mosbacher, V. C. Antochi, M. Weiss, Julien Masbou, Kentaro Miuchi, C. Therreau, J. R. Angevaare, J. Howlett, H. Qiu, J. Palacio, Shingo Kazama, F. Semeria, M. Alfonsi, Jan Conrad, Masanori Kobayashi, Masaki Yamashita, Fabrizio Marignetti, L. Bellagamba, P. Gaemers, F. Lombardi, V. Pizzella, J. Naganoma, Shigetaka Moriyama, M. Murra, C. Capelli, K. Morå, T. Zhu, F. D. Amaro, Guillaume Plante, Boris Bauermeister, D. Thers, R. F. Lang, IoP (FNWI), XENON (IHEF, IoP, FNWI), Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), XENON, Columbia University [New York], Oskar Klein Centre [Stockholm], Stockholm University, University of Bologna, Johannes Gutenberg - Universität Mainz (JGU), Westfälische Wilhelms-Universität Münster (WWU), University of Coimbra [Portugal] (UC), Università degli studi di Torino (UNITO), University of Amsterdam [Amsterdam] (UvA), New York University [Abu Dhabi], NYU System (NYU), Aprile, E., Aalbers, J., Agostini, F., Alfonsi, M., Althueser, L., Amaro, F. D., Antochi, V. C., Angelino, E., Angevaare, J. R., Arneodo, F., Barge, D., Baudis, L., Bauermeister, B., Bellagamba, L., Benabderrahmane, M. L., Berger, T., Brown, A., Brown, E., Bruenner, S., Bruno, G., Budnik, R., Capelli, C., Cardoso, J. M. R., Cichon, D., Cimmino, B., Clark, M., Coderre, D., Colijn, A. P., Conrad, J., Cussonneau, J. P., Decowski, M. P., Depoian, A., Di Gangi, P., Di Giovanni, A., Di Stefano, R., Diglio, S., Elykov, A., Eurin, G., Ferella, A. D., Fulgione, W., Gaemers, P., Gaior, R., Galloway, M., Gao, F., Grandi, L., Hasterok, C., Hils, C., Hiraide, K., Hoetzsch, L., Howlett, J., Iacovacci, M., Itow, Y., Joerg, F., Kato, N., Kazama, S., Kobayashi, M., Koltman, G., Kopec, A., Landsman, H., Lang, R. F., Levinson, L., Lin, Q., Lindemann, S., Lindner, M., Lombardi, F., Long, J., Lopes, J. A. M., Fune, E. L., Macolino, C., Mahlstedt, J., Mancuso, A., Manenti, L., Manfredini, A., Marignetti, F., Undagoitia, T. M., Martens, K., Masbou, J., Masson, D., Mastroianni, S., Messina, M., Miuchi, K., Mizukoshi, K., Molinario, A., Mora, K., Moriyama, S., Mosbacher, Y., Murra, M., Naganoma, J., Ni, K., Oberlack, U., Odgers, K., Palacio, J., Pelssers, B., Peres, R., Pienaar, J., Pizzella, V., Plante, G., Qin, J., Qiu, H., Garcia, D. R., Reichard, S., Rocchetti, A., Rupp, N., Dos Santos, J. M. F., Sartorelli, G., Sarcevic, N., Scheibelhut, M., Schreiner, J., Schulte, D., Schumann, M., Lavina, L. S., Selvi, M., Semeria, F., Shagin, P., Shockley, E., Silva, M., Simgen, H., Takeda, A., Therreau, C., Thers, D., Toschi, F., Trinchero, G., Tunnell, C., Valerius, K., Vargas, M., Volta, G., Wang, H., Wei, Y., Weinheimer, C., Weiss, M., Wenz, D., Wittweg, C., Xu, Z., Yamashita, M., Ye, J., Zavattini, G., Zhang, Y., Zhu, T., Zopounidis, J. P., Amaro, F.D., Antochi, V.C., Angevaare, J.R., Benabderrahmane, M.L., Cardoso, J.M.R., Colijn, A.P., Cussonneau, J.P., Decowski, M.P., Gangi, P. Di, Giovanni, A. Di, Stefano, R. Di, Ferella, A.D., Lang, R.F., Lopes, J.A.M., Fune, E. López, Undagoitia, T. Marrodán, Morå, K., García, D. Ramírez, Santos, J.M.F. do, Šarčević, N., Lavina, L. Scotto, and Zopounidis, J.P.

Subjects
WIMP nucleon: scattering, data analysis method, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Physics - Instrumentation and Detectors, Hadron, Dark matter, FOS: Physical sciences, Elementary particle, dark matter: direct detection, 01 natural sciences, WIMP: dark matter, High Energy Physics - Experiment, NO, Nuclear physics, High Energy Physics - Experiment (hep-ex), XENON, PE2_2, WIMP, PE2_1, electron: recoil, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Neutron, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], 010306 general physics, PE2_4, Dark matter experiment, ComputingMilieux_MISCELLANEOUS, activity report, nucleus: recoil, Physics, xenon: liquid, 010308 nuclear & particles physics, background, Astronomy and Astrophysics, Instrumentation and Detectors (physics.ins-det), Dark matter experiments, dark matter simulations, sensitivity, Baryon, Dark matter experiments, Dark matter simulations, Weakly interacting massive particles, Nucleon, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

XENONnT is a dark matter direct detection experiment, utilizing 5.9 t of instrumented liquid xenon, located at the INFN Laboratori Nazionali del Gran Sasso. In this work, we predict the experimental background and project the sensitivity of XENONnT to the detection of weakly interacting massive particles (WIMPs). The expected average differential background rate in the energy region of interest, corresponding to (1, 13) keV and (4, 50) keV for electronic and nuclear recoils, amounts to 12.3 ± 0.6 (keV t y)-1 and (2.2± 0.5)× 10−3 (keV t y)-1, respectively, in a 4 t fiducial mass. We compute unified confidence intervals using the profile construction method, in order to ensure proper coverage. With the exposure goal of 20 t y, the expected sensitivity to spin-independent WIMP-nucleon interactions reaches a cross-section of 1.4×10−48 cm2 for a 50 GeV/c2 mass WIMP at 90% confidence level, more than one order of magnitude beyond the current best limit, set by XENON1T . In addition, we show that for a 50 GeV/c2 WIMP with cross-sections above 2.6×10−48 cm2 (5.0×10−48 cm2) the median XENONnT discovery significance exceeds 3σ (5σ). The expected sensitivity to the spin-dependent WIMP coupling to neutrons (protons) reaches 2.2×10−43 cm2 (6.0×10−42 cm2).

Published
2020

12. Excess electronic recoil events in XENON1T

Author

A. Manfredini, L. Scotto Lavina, A. D. Ferella, Hongwei Wang, L. Levinson, Ch. Weinheimer, D. Masson, J. Pienaar, Qing Lin, Auke-Pieter Colijn, Laura Baudis, E. Angelino, João Cardoso, T. Zhu, J. R. Angevaare, F. Gao, Jelle Aalbers, P. Gaemers, F. Toschi, A. Di Giovanni, R. Di Stefano, W. Fulgione, Gabriella Sartorelli, M. Clark, Kentaro Miuchi, C. Therreau, Yuehuan Wei, F. D. Amaro, H. Landsman, A. Depoian, Guillaume Plante, J. Ye, M. Selvi, Joern Mahlstedt, M. L. Benabderrahmane, Ethan Brown, D. Wenz, J. Qin, M. Alfonsi, R. Peres, D. Schulte, J. Long, J. P. Zopounidis, S. Moriyama, Boris Bauermeister, G. Eurin, R. Gaior, C. Hasterok, Ran Budnik, J.M.F. dos Santos, A. Kopec, Xavier Mougeot, Yoshitaka Itow, Michelle Galloway, C. Macolino, F. Agostini, N. Kato, J. Palacio, E. Shockley, A. Mancuso, M. Weiss, S. Reichard, Yanxi Zhang, L. Grandi, J. Schreiner, Sebastian Lindemann, M. P. Decowski, Shingo Kazama, Laura Manenti, G. Koltman, Marc Schumann, Manfred Lindner, R. F. Lang, E. López Fune, N. Rupp, P. Di Gangi, Guido Zavattini, F. Lombardi, Jan Conrad, S. Mastroianni, Uwe Oberlack, C. Hils, Masanori Kobayashi, F. Marignetti, S. Bruenner, Kaixuan Ni, K. Mizukoshi, F. Semeria, D. Ramírez García, V. Pizzella, N. Šarčević, Giacomo Bruno, T. Berger, Sara Diglio, A. Takeda, Masaki Yamashita, Y. Mosbacher, J. Howlett, Gian Carlo Trinchero, H. Qiu, A. Elykov, Lorenzo Bellagamba, F. Arneodo, Katsuki Hiraide, J. Naganoma, A. Rocchetti, D. Barge, B. Cimmino, G. Volta, M. Murra, V. C. Antochi, C. Capelli, P. Shagin, L. Hoetzsch, K. Morå, Julien Masbou, H. Simgen, Dominique Thers, C. Wittweg, K. Odgers, D. Coderre, Manuel Gameiro da Silva, A. Molinario, M. Scheibelhut, April S. Brown, Jean-Pierre Cussonneau, Z. Xu, D. Cichon, Bart Pelssers, K. Martens, M. Messina, Elena Aprile, F. Joerg, C. Tunnell, M. Vargas, T. Marrodán Undagoitia, J. A. M. Lopes, M. Iacovacci, L. Althueser, Columbia University [New York], Oskar Klein Centre [Stockholm], Stockholm University, University of Bologna, Johannes Gutenberg - Universität Mainz (JGU), Westfälische Wilhelms-Universität Münster (WWU), University of Coimbra [Portugal] (UC), Università degli studi di Torino (UNITO), University of Amsterdam [Amsterdam] (UvA), New York University [Abu Dhabi], NYU System (NYU), Aprile, E., Aalbers, J., Agostini, F., Alfonsi, M., Althueser, L., Amaro, F. D., Antochi, V. C., Angelino, E., Angevaare, J. R., Arneodo, F., Barge, D., Baudis, L., Bauermeister, B., Bellagamba, L., Benabderrahmane, M. L., Berger, T., Brown, A., Brown, E., Bruenner, S., Bruno, G., Budnik, R., Capelli, C., Cardoso, J. M. R., Cichon, D., Cimmino, B., Clark, M., Coderre, D., Colijn, A. P., Conrad, J., Cussonneau, J. P., Decowski, M. P., Depoian, A., Di Gangi, P., Di Giovanni, A., Di Stefano, R., Diglio, S., Elykov, A., Eurin, G., Ferella, A. D., Fulgione, W., Gaemers, P., Gaior, R., Galloway, M., Gao, F., Grandi, L., Hasterok, C., Hils, C., Hiraide, K., Hoetzsch, L., Howlett, J., Iacovacci, M., Itow, Y., Joerg, F., Kato, N., Kazama, S., Kobayashi, M., Koltman, G., Kopec, A., Landsman, H., Lang, R. F., Levinson, L., Lin, Q., Lindemann, S., Lindner, M., Lombardi, F., Long, J., Lopes, J. A. M., López Fune, E., Macolino, C., Mahlstedt, J., Mancuso, A., Manenti, L., Manfredini, A., Marignetti, F., Marrodán Undagoitia, T., Martens, K., Masbou, J., Masson, D., Mastroianni, S., Messina, M., Miuchi, K., Mizukoshi, K., Molinario, A., Morå, K., Moriyama, S., Mosbacher, Y., Murra, M., Naganoma, J., Ni, K., Oberlack, U., Odgers, K., Palacio, J., Pelssers, B., Peres, R., Pienaar, J., Pizzella, V., Plante, G., Qin, J., Qiu, H., Ramírez García, D., Reichard, S., Rocchetti, A., Rupp, N., dos Santos, J. M. F., Sartorelli, G., Šarčević, N., Scheibelhut, M., Schreiner, J., Schulte, D., Schumann, M., Scotto Lavina, L., Selvi, M., Semeria, F., Shagin, P., Shockley, E., Silva, M., Simgen, H., Takeda, A., Therreau, C., Thers, D., Toschi, F., Trinchero, G., Tunnell, C., Vargas, M., Volta, G., Wang, H., Wei, Y., Weinheimer, C., Weiss, M., Wenz, D., Wittweg, C., Xu, Z., Yamashita, M., Ye, J., Zavattini, G., Zhang, Y., Zhu, T., Zopounidis, J. P., Mougeot, X., Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Intégration des Systèmes et des Technologies (LIST), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, XENON, University of Bologna/Università di Bologna, Istituto Nazionale di Fisica Nucleare, Sezione di Bologna (INFN, Sezione di Bologna), Istituto Nazionale di Fisica Nucleare (INFN), Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU), Westfälische Wilhelms-Universität Münster = University of Münster (WWU), Università degli studi di Torino = University of Turin (UNITO), Istituto Nazionale di Fisica Nucleare, Sezione di Torino (INFN, Sezione di Torino), National Institute for Subatomic Physics [Amsterdam] (NIKHEF), Universität Zürich [Zürich] = University of Zurich (UZH), Rensselaer Polytechnic Institute (RPI), Weizmann Institute of Science [Rehovot, Israël], Max-Planck-Institut für Kernphysik (MPIK), Max-Planck-Gesellschaft, Istituto Nazionale di Fisica Nucleare, Sezione di Napoli (INFN, Sezione di Napoli), Purdue University [West Lafayette], Albert-Ludwigs-Universität Freiburg, Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), University of L'Aquila [Italy] (UNIVAQ), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Kavli Institute for Cosmological Physics [Chicago] (KICP), University of Chicago, The University of Tokyo (UTokyo), Nagoya University, Konan University [Kobe, Japan], University of California [San Diego] (UC San Diego), University of California (UC), Rice University [Houston], University of California [Los Angeles] (UCLA), Laboratoire National Henri Becquerel (LNHB), Département Métrologie Instrumentation & Information (DM2I), Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département d'instrumentation Numérique (DIN (CEA-LIST)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), XENON collaboration, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), University of California, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire d'Intégration des Systèmes et des Technologies (LIST), IoP (FNWI), and XENON (IHEF, IoP, FNWI)

Subjects
xenon: target, axions, solar axion, magnetic moment, dimension: 3, neutrino: solar, Physics beyond the Standard Model, Solar neutrino, dark matter: direct detection, 01 natural sciences, 7. Clean energy, High Energy Physics - Experiment, Dark matter, direct detection, axion, High Energy Physics - Experiment (hep-ex), neutrino, XENON, High Energy Physics - Phenomenology (hep-ph), background: low, Recoil, electron: recoil, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], beta-rays, Particle Physics Experiments, coupling: (axion 2electron), multi-purpose particle detector, nuclear instrumentation, ComputingMilieux_MISCELLANEOUS, instrumentation, Physics, xenon: liquid, boson: dark matter, axion 2nucleon, tritium, new physics: search for, semileptonic decay, boson: vector, tension, neutrino: magnetic moment, High Energy Physics - Phenomenology, axion 2photon, low background, boson, Neutrino, ionizing radiation, Nucleon, Astrophysics - Cosmology and Nongalactic Astrophysics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), dark matter detector, electronic recoil, Electron capture, XENON1T detector, Dark matter, low-energy electronic recoil data, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], dark matter, NO, Nuclear physics, PE2_2, PE2_1, tritium: semileptonic decay, 0103 physical sciences, solar axion model, surface, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], axion: coupling, PE2_4, 010306 general physics, pseudoscalar, Axion, dark matter: vector, dark matter, XENON1T detector, electronic recoil, solar neutrino, detector, Dark Matter, Axions, Beta Decay, Liquid Xenon, TPC, 010308 nuclear & particles physics, axion 2electron, coupling: (axion 2nucleon), dark matter: detector, model: axion, Gran Sasso, metrology, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], axion, stellar constraints, coupling: (axion 2photon), High Energy Physics::Experiment, particle dark matter, direct detection, beta decay, axion: solar, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], experimental results
Abstract

We report results from searches for new physics with low-energy electronic recoil data recorded with the XENON1T detector. With an exposure of 0.65 t-y and an unprecedentedly low background rate of $76\pm2$ events/(t y keV) between 1 and 30 keV, the data enables sensitive searches for solar axions, an enhanced neutrino magnetic moment, and bosonic dark matter. An excess over known backgrounds is observed at low energies and most prominent between 2 and 3 keV. The solar axion model has a 3.4$\sigma$ significance, and a 3D 90% confidence surface is reported for axion couplings to electrons, photons, and nucleons. This surface is inscribed in the cuboid defined by $g_{ae}, Comment: 26 pages, 15 figures. v2 added Ar37 background discussion and best-fit mass of bosonic dark matter, v3 updated Ar37 discussion, tritium estimation, and solar axion energy spectrum. Data in Fig. 2, 4, and 15, including unbinned energy points in Fig. 4, are available in 10.5281/zenodo.4088778

Published
2020

13. Plasmonics beyond noble metals: Exploiting phaseand compositional changes for manipulatingplasmonic performance

Author

Yael Gutiérrez, April S. Brown, Fernando Moreno, and Maria Losurdo

Abstract

Reconfigurable plasmonics constitutes an exciting and challenging new horizon in nanophotonics. This blooming field aims at providingplasmonic nanostructures that present a dynamic and active plasmonic response that can be switched or manipulated by external stimuli toinduce a controllable change in the optical properties. Most common plasmonic materials, such as the noble metals gold and silver, cannotdeliver this type of behavior. Therefore, significant effort is being invested in developing alternative materials whose optical properties canbe controllably modified to provide a reconfigurable plasmonic response. In this perspective, several materials including non-noble metals,transition metal oxides and nitrides, and chalcogenide compounds will be analyzed. The selected materials share interesting characteristicslike low cost, good chemical and thermal stabilities, and CMOS compatibility while presenting a reconfigurable plasmonic response gov-erned by different phase-change mechanisms.

Published
2020

14. Polymorphic gallium for active resonance tuning in photonic nanostructures: from bulk gallium to two-dimensional (2D) gallenene

Author

Maria Losurdo, April S. Brown, Fernando Moreno, Javier Junquera, Pablo García-Fernández, Yael Gutiérrez, and Universidad de Cantabria

Subjects
Resonance tuning, Nanostructure, Materials science, QC1-999, chemistry.chemical_element, Nanotechnology, Gallium, Reconfigurable plasmonics, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Nanomaterials, Phase-change materials, Electrical and Electronic Engineering, Gallenene, business.industry, Physics, 021001 nanoscience & nanotechnology, Atomic and Molecular Physics, and Optics, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, Active plasmonics, chemistry, Christian ministry, Photonics, 0210 nano-technology, business, Biotechnology
Abstract

Reconfigurable plasmonics is driving an extensive quest for active materials that can support a controllable modulation of their optical properties for dynamically tunable plasmonic structures. Here, polymorphic gallium (Ga) is demonstrated to be a very promising candidate for adaptive plasmonics and reconfigurable photonics applications. The Ga sp-metal is widely known as a liquid metal at room temperature. In addition to the many other compelling attributes of nanostructured Ga, including minimal oxidation and biocompatibility, its six phases have varying degrees of metallic character, providing a wide gamut of electrical conductivity and optical behavior tunability. Here, the dielectric function of the several Ga phases is introduced and correlated with their respective electronic structures. The key conditions for optimal optical modulation and switching for each Ga phase are evaluated. Additionally, we provide a comparison of Ga with other more common phase-change materials, showing better performance of Ga at optical frequencies. Furthermore, we first report, to the best of our knowledge, the optical properties of liquid Ga in the terahertz (THz) range showing its broad plasmonic tunability from ultraviolet to visible-infrared and down to the THz regime. Finally, we provide both computational and experimental evidence of extension of Ga polymorphism to bidimensional twodimensional (2D) gallenene, paving the way to new bidimensional reconfigurable plasmonic platforms. F.M. acknowledges MICINN (Spanish Ministry of Science and Innovation) through project PGC2018-096649-B-100.

Published
2020

17. Solar neutrino detection sensitivity in DARWIN via electron scattering

Author

J. J. Cuenca-García, G. Volta, C. Hils, M. L. Benabderrahmane, M. P. Decowski, Ethan Brown, V. C. Antochi, Manfred Lindner, G. Iaquaniello, J. Mahlstedt, Yuehuan Wei, Michelle Galloway, A. Manfredini, Joachim Wolf, H. Schulze Eißing, S. Stern, D. Giovagnoli, M. Kleifges, K. Thieme, P. Di Gangi, S. Brünner, D. Douillet, T. Zhu, F. D. Amaro, Guillaume Plante, G. Khundzakishvili, Ch. Bourgeois, L. Scotto Lavina, Ferenc Glück, Kaixuan Ni, J. Pienaar, F. Toennies, Hardy Simgen, A. D. Ferella, C. Therreau, W. Shen, K. Eitel, Jelle Aalbers, D. Wenz, Bojan Milosevic, G. Koltmann, M. Clark, J. Howlett, A. Terliuk, Roberto Trotta, S. Milutinovic, P. Sanchez-Lucas, Sara Diglio, M. Balzer, Ch. Weinheimer, P. A. Breur, K. Odgers, R. Meyer, A. Depoian, F. Girard, M. Murra, Amos Breskin, H. Fischer, G. Sartorelli, Julien Masbou, I. Ostrovskiy, M. Selvi, T. Marrodán Undagoitia, P. Meinhardt, Biljana Antunović, J. Kellerer, Laura Baudis, Michael Wurm, L. Grandi, D. Baur, T. K. Kleiner, H. Landsman, A. Bismark, D. Ramírez García, L. Althueser, P. Gaemers, A. Kopec, A. Molinario, Y. Zhu, A. Loya Villalpando, M. Keller, Y. Mosbacher, Y. Ma, Mila Pandurovic, Andreas Kopmann, Ralph Engel, Jean-Pierre Cussonneau, Guido Drexlin, Kai Zuber, P. Szabo, Bart Pelssers, J. Qin, Y. Biondi, J.M.F. dos Santos, D. Masson, N. Rupp, F. Kuger, Giacomo Bruno, P. Shagin, J. A. M. Lopes, F. Agostini, Uwe Oberlack, L. LaCascio, C. Tunnell, S. Hansmann-Menzemer, Bernhard Holzapfel, Y. Xing, R. Größle, Sebastian Lindemann, J. Palacio, C. Wittweg, S. Wuestling, D. Vorkapic, M. Obradovic, Benjamin Kilminster, J. R. Angevaare, D. Schulte, Manuel Gameiro da Silva, Steffen Grohmann, Marc Weber, J. Qi, W. Fulgione, Eef Masson, J. P. Zopounidis, C.M.B. Monteiro, Jan Conrad, A. Di Giovanni, S. Reichard, R. Glade-Beucke, Lawrence M. Krauss, M. Weiss, M. Steidl, D. Cichon, D. Thers, J. Dierle, S. Sharma, Elena Aprile, João Cardoso, M. Pierre, R. F. Lang, R. Gumbsheimer, F. Gao, April S. Brown, N. McFadden, H-C. Schultz-Coulon, E. Erdal, F. Arneodo, C. Macolino, F. Lombardi, V. Pizzella, Volker Hannen, Peter Fischer, F. Jörg, C. Capelli, K. Morå, R. Budnik, M. Alfonsi, Kathrin Valerius, S. E. M. Ahmed Maouloud, E. Morteau, Lior Arazi, Marc Schumann, R. Peres, D. Subotic, A. P. Colijn, Jayden L. Newstead, Aalbers, J., Agostini, F., Maouloud, S. E. M. Ahmed, Alfonsi, M., Althueser, L., Amaro, F. D., Angevaare, J., Antochi, V. C., Antunovic, B., Aprile, E., Arazi, L., Arneodo, F., Balzer, M., Baudis, L., Baur, D., Benabderrahmane, M. L., Biondi, Y., Bismark, A., Bourgeois, C., Breskin, A., Breur, P. A., Brown, A., Brown, E., Brünner, S., Bruno, G., Budnik, R., Capelli, C., Cardoso, J., Cichon, D., Clark, M., Colijn, A. P., Conrad, J., Cuenca-García, J. J., Cussonneau, J. P., Decowski, M. P., Depoian, A., Dierle, J., Gangi, P. Di, Giovanni, A. Di, Diglio, S., Douillet, D., Drexlin, G., Eitel, K., Engel, R., Erdal, E., Ferella, A. D., Fischer, H., Fischer, P., Fulgione, W., Gaemers, P., Galloway, M., Gao, F., Giovagnoli, D., Girard, F., Glade-Beucke, R., Glück, F., Grandi, L., Grohmann, S., Größle, R., Gumbsheimer, R., Hannen, V., Hansmann-Menzemer, S., Hils, C., Holzapfel, B., Howlett, J., Iaquaniello, G., Jörg, F., Keller, M., Kellerer, J., Khundzakishvili, G., Kilminster, B., Kleifges, M., Kleiner, T. K., Koltmann, G., Kopec, A., Kopmann, A., Krauss, L. M., Kuger, F., LaCascio, L., Landsman, H., Lang, R. F., Lindemann, S., Lindner, M., Lombardi, F., Lopes, J. A. M., Villalpando, A. Loya, Ma, Y., Macolino, C., Mahlstedt, J., Manfredini, A., Undagoitia, T. Marrodán, Masbou, J., Masson, D., Masson, E., McFadden, N., Meinhardt, P., Meyer, R., Milosevic, B., Milutinovic, S., Molinario, A., Monteiro, C. M. B., Morå, K., Morteau, E., Mosbacher, Y., Murra, M., Newstead, J. L., Ni, K., Oberlack, U. G., Obradovic, M., Odgers, K., Ostrovskiy, I., Palacio, J., Pandurovic, M., Pelssers, B., Peres, R., Pienaar, J., Pierre, M., Pizzella, V., Plante, G., Qi, J., Qin, J., García, D. Ramírez, Reichard, S. E., Rupp, N., Sanchez-Lucas, P., dos Santos, J. M. F., Sartorelli, G., Schulte, D., Schultz-Coulon, H. C., Schulze Eißing, H., Schumann, M., Lavina, L. Scotto, Selvi, M., Shagin, P., Sharma, S., Shen, W., Silva, M., Simgen, H., Steidl, M., Stern, S., Subotic, D., Szabo, P., Terliuk, A., Therreau, C., Thers, D., Thieme, K., Toennies, F., Trotta, R., Tunnell, C. D., Valerius, K., Volta, G., Vorkapic, D., Weber, M., Wei, Y., Weinheimer, C., Weiss, M., Wenz, D., Wittweg, C., Wolf, J., Wuestling, S., Wurm, M., Xing, Y., Zhu, T., Zhu, Y., Zopounidis, J. P., Zuber, K., Oskar Klein Centre [Stockholm], Stockholm University, University of Bologna, Johannes Gutenberg - Universität Mainz (JGU), Westfälische Wilhelms-Universität Münster (WWU), Columbia University [New York], Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), DARWIN, Science and Technology Facilities Council (STFC), IoP (FNWI), XENON (IHEF, IoP, FNWI), and DARWIN Collaboration

Subjects
electron, Physics - Instrumentation and Detectors, Physics and Astronomy (miscellaneous), neutrino: solar, Physics::Instrumentation and Detectors, Solar neutrino, elastic scattering, Elementary particle, 7. Clean energy, 01 natural sciences, neutrino: flux, High Energy Physics - Experiment, Physics, Particles & Fields, XENON, High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology (hep-ph), [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], physics.ins-det, Physics, xenon: liquid, Weinberg angle, double-beta decay, hep-ph, Instrumentation and Detectors (physics.ins-det), Nuclear & Particles Physics, Massless particle, observatory, High Energy Physics - Phenomenology, neutrino: detector, Astrophysics - Solar and Stellar Astrophysics, Neutrino detector, Physical Sciences, 0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics, ddc:620, Neutrino, model: solar, astro-ph.SR, boron: nuclide, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, lcsh:Astrophysics, Nuclear physics, oxygen: nuclide, Settore FIS/05 - Astronomia e Astrofisica, Double beta decay, nitrogen: nuclide, neutrino nucleus: elastic scattering, lcsh:QB460-466, 0103 physical sciences, electron: recoil: energy, lcsh:Nuclear and particle physics. Atomic energy. Radioactivity, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], 010306 general physics, 0206 Quantum Physics, Engineering (miscellaneous), Engineering & allied operations, Solar and Stellar Astrophysics (astro-ph.SR), Science & Technology, hep-ex, 010308 nuclear & particles physics, beryllium: nuclide, sensitivity, Neutrino, Sun, Dark Matter, Direct Detection, Xenon, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], lcsh:QC770-798, High Energy Physics::Experiment, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Lepton
Abstract

We detail the sensitivity of the liquid xenon (LXe) DARWIN observatory to solar neutrinos via elastic electron scattering. We find that DARWIN will have the potential to measure the fluxes of five solar neutrino components: $pp$, $^7$Be, $^{13}$N, $^{15}$O and $pep$. The precision of the $^{13}$N, $^{15}$O and $pep$ components is hindered by the double-beta decay of $^{136}$Xe and, thus, would benefit from a depleted target. A high-statistics observation of $pp$ neutrinos would allow us to infer the values of the weak mixing angle, $\sin^2\theta_w$, and the electron-type neutrino survival probability, $P_e$, in the electron recoil energy region from a few keV up to 200 keV for the first time, with relative precision of 5% and 4%, respectively, at an exposure of 300 ty. An observation of $pp$ and $^7$Be neutrinos would constrain the neutrino-inferred solar luminosity down to 0.2%. A combination of all flux measurements would distinguish between the high (GS98) and low metallicity (AGS09) solar models with 2.1-2.5$\sigma$ significance, independent of external measurements from other experiments or a measurement of $^8$B neutrinos through coherent elastic neutrino-nucleus scattering in DARWIN. Finally, we demonstrate that with a depleted target DARWIN may be sensitive to the neutrino capture process of $^{131}$Xe., Comment: 9 pages, 4 figures; for associated data files, see https://github.com/Physik-Institut-UZH/DARWIN-Sensitivity-Studies/tree/master/solar_neutrinos_electron_scattering

Published
2020

18. 705 Rates of Surgical Intervention in Aboriginal Patients With Significant Rheumatic Heart Disease

Author

Ajay Sinhal, N. Kangaharan, Derek P. Chew, April S. Brown, Stephen J. Nicholls, Peter J. Psaltis, A. Baumann, Alex Kaethner, Jayme Bennetts, B. Remenyi, Ross L. Roberts-Thomson, Marcus Ilton, J. Reade, and L. Culgan

Subjects
Pulmonary and Respiratory Medicine, medicine.medical_specialty, Heart disease, business.industry, Internal medicine, Intervention (counseling), medicine, Cardiology and Cardiovascular Medicine, medicine.disease, business
Published
2020

19. 006 Left Atrial Ejection Fraction Predicts Future need for Surgery in Asymptomatic Patients With Rheumatic Mitral Valve Disease

Author

L. Culgan, A. Baumann, Alex Kaethner, Peter J. Psaltis, Gavin R. Wheaton, H. Tayeb, April S. Brown, B. Remenyi, Ross L. Roberts-Thomson, Marcus Ilton, J. Reade, N. Kangaharan, Stephen J. Nicholls, and M. Mu

Subjects
Pulmonary and Respiratory Medicine, medicine.medical_specialty, Ejection fraction, business.industry, Disease, Asymptomatic, Surgery, medicine.anatomical_structure, Left atrial, Mitral valve, Medicine, medicine.symptom, Cardiology and Cardiovascular Medicine, business
Published
2020

20. Search for Light Dark Matter Interactions Enhanced by the Migdal Effect or Bremsstrahlung in XENON1T

Author

A. Depoian, T. Berger, J. Qin, M. Selvi, T. Zhu, F. D. Amaro, H. Landsman, Guillaume Plante, N. Rupp, M. Iacovacci, Qing Lin, Boris Bauermeister, A. Kopec, N. Upole, D. Cichon, D. Wenz, R. F. Lang, R. Peres, B. Riedel, N. Šarčević, Shingo Kazama, W. Fulgione, P. Di Gangi, K. Morå, M. Messina, P. A. Breur, M. Manenti, J. Ye, Kaixuan Ni, F. Joerg, L. Althueser, A. Elykov, R. Podviianiuk, M. Murra, Elena Aprile, S. Schindler, C. Capelli, Yanxi Zhang, M. Alfonsi, C. Therreau, F. Arneodo, Gian Carlo Trinchero, D. Schulte, Jan Conrad, C. Hasterok, April S. Brown, R. Itay, E. Angelino, Ran Budnik, Uwe Oberlack, F. Toschi, Fabrizio Marignetti, J. Fei, F. Lombardi, D. Ramírez García, Yuehuan Wei, V. Pizzella, M. Garbini, L. Bellagamba, Y. Mosbacher, Giacomo Bruno, A. Di Giovanni, C. Macolino, Jörn Mahlstedt, J. Naganoma, J. P. Zopounidis, Michelle Galloway, J. Howlett, M. L. Benabderrahmane, S. Reichard, O. Wack, Ethan Brown, Marc Schumann, H. Qiu, C. Hils, A. Manfredini, L. Levinson, J. Schreiner, K. Odgers, S. Bruenner, J. Wulf, J. Palacio, Julien Masbou, H. Simgen, M. P. Decowski, Manfred Lindner, J. Pienaar, M. Kobayashi, G. Eurin, K. Micheneau, E. Shockley, Jelle Aalbers, Gabriella Sartorelli, L. Scotto Lavina, Auke-Pieter Colijn, Kate C. Miller, A. D. Ferella, Hongwei Wang, Ch. Weinheimer, J. A. M. Lopes, A. Kish, A. Gallo Rosso, M. Vargas, T. Marrodán Undagoitia, A. Rocchetti, Jean-Pierre Cussonneau, Bart Pelssers, C. Tunnell, C. Wittweg, A. Fieguth, D. Coderre, L. Grandi, G. Koltman, Manuel Gameiro da Silva, A. Molinario, M. Scheibelhut, D. Barge, G. Volta, E. Hogenbirk, V. C. Antochi, P. Shagin, Laura Baudis, Dominique Thers, P. Gaemers, Z. Greene, J.M.F. dos Santos, F. Agostini, Sebastian Lindemann, E. López Fune, S. Mastroianni, Sara Diglio, João Cardoso, F. Gao, P. de Perio, Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de l'Accélérateur Linéaire (LAL), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), XENON, Aprile, E., Aalbers, J., Agostini, F., Alfonsi, M., Althueser, L., Amaro, F. D., Antochi, V. C., Angelino, E., Arneodo, F., Barge, D., Baudis, L., Bauermeister, B., Bellagamba, L., Benabderrahmane, M. L., Berger, T., Breur, P. A., Brown, A., Brown, E., Bruenner, S., Bruno, G., Budnik, R., Capelli, C., Cardoso, J. M. R., Cichon, D., Coderre, D., Colijn, A. P., Conrad, J., Cussonneau, J. P., Decowski, M. P., de Perio, P., Depoian, A., Di Gangi, P., Di Giovanni, A., Diglio, S., Elykov, A., Eurin, G., Fei, J., Ferella, A. D., Fieguth, A., Fulgione, W., Gaemers, P., Gallo Rosso, A., Galloway, M., Gao, F., Garbini, M., Grandi, L., Greene, Z., Hasterok, C., Hils, C., Hogenbirk, E., Howlett, J., Iacovacci, M., Itay, R., Joerg, F., Kazama, S., Kish, A., Kobayashi, M., Koltman, G., Kopec, A., Landsman, H., Lang, R. F., Levinson, L., Lin, Q., Lindemann, S., Lindner, M., Lombardi, F., Lopes, J. A. M., López Fune, E., Macolino, C., Mahlstedt, J., Manenti, M., Manfredini, A., Marignetti, F., Marrodán Undagoitia, T., Masbou, J., Mastroianni, S., Messina, M., Micheneau, K., Miller, K., Molinario, A., Morå, K., Mosbacher, Y., Murra, M., Naganoma, J., Ni, K., Oberlack, U., Odgers, K., Palacio, J., Pelssers, B., Peres, R., Pienaar, J., Pizzella, V., Plante, G., Podviianiuk, R., Qin, J., Qiu, H., Ramírez García, D., Reichard, S., Riedel, B., Rocchetti, A., Rupp, N., dos Santos, J. M. F., Sartorelli, G., Šarčević, N., Scheibelhut, M., Schindler, S., Schreiner, J., Schulte, D., Schumann, M., Scotto Lavina, L., Selvi, M., Shagin, P., Shockley, E., Silva, M., Simgen, H., Therreau, C., Thers, D., Toschi, F., Trinchero, G., Tunnell, C., Upole, N., Vargas, M., Volta, G., Wack, O., Wang, H., Wei, Y., Weinheimer, C., Wenz, D., Wittweg, C., Wulf, J., Ye, J., Zhang, Y., Zhu, T., Zopounidis, J. P., Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), XENON (IHEF, IoP, FNWI), IoP (FNWI), Aprile E., Aalbers J., Agostini F., Alfonsi M., Althueser L., Amaro F.D., Antochi V.C., Angelino E., Arneodo F., Barge D., Baudis L., Bauermeister B., Bellagamba L., Benabderrahmane M.L., Berger T., Breur P.A., Brown A., Brown E., Bruenner S., Bruno G., Budnik R., Capelli C., Cardoso J.M.R., Cichon D., Coderre D., Colijn A.P., Conrad J., Cussonneau J.P., Decowski M.P., De Perio P., Depoian A., Di Gangi P., Di Giovanni A., Diglio S., Elykov A., Eurin G., Fei J., Ferella A.D., Fieguth A., Fulgione W., Gaemers P., Gallo Rosso A., Galloway M., Gao F., Garbini M., Grandi L., Greene Z., Hasterok C., Hils C., Hogenbirk E., Howlett J., Iacovacci M., Itay R., Joerg F., Kazama S., Kish A., Kobayashi M., Koltman G., Kopec A., Landsman H., Lang R.F., Levinson L., Lin Q., Lindemann S., Lindner M., Lombardi F., Lopes J.A.M., Lopez Fune E., MacOlino C., Mahlstedt J., Manenti M., Manfredini A., Marignetti F., Marrodan Undagoitia T., Masbou J., Mastroianni S., Messina M., Micheneau K., Miller K., Molinario A., Mora K., Mosbacher Y., Murra M., Naganoma J., Ni K., Oberlack U., Odgers K., Palacio J., Pelssers B., Peres R., Pienaar J., Pizzella V., Plante G., Podviianiuk R., Qin J., Qiu H., Ramirez Garcia D., Reichard S., Riedel B., Rocchetti A., Rupp N., Dos Santos J.M.F., Sartorelli G., Sarcevic N., Scheibelhut M., Schindler S., Schreiner J., Schulte D., Schumann M., Scotto Lavina L., Selvi M., Shagin P., Shockley E., Silva M., Simgen H., Therreau C., Thers D., Toschi F., Trinchero G., Tunnell C., Upole N., Vargas M., Volta G., Wack O., Wang H., Wei Y., Weinheimer C., Wenz D., Wittweg C., Wulf J., Ye J., Zhang Y., Zhu T., and Zopounidis J.P.

Subjects
xenon: target, Physics - Instrumentation and Detectors, dark matter: interaction, elastic scattering, General Physics and Astronomy, 01 natural sciences, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Xenon, Ionization, excited state, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment, Light dark matter, Elastic scattering, Physics, xenon: liquid, atom, momentum transfer, Momentum transfer, Bremsstrahlung, Instrumentation and Detectors (physics.ins-det), photon: bremsstrahlung, S030DN5, Weakly interacting massive particles, Excited state, Astrophysics - Cosmology and Nongalactic Astrophysics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Dark matter, Light Dark Matter Direct search Liquid Xenon TPC, FOS: Physical sciences, S030DI5, chemistry.chemical_element, Nuclear physics, Particle dark matter, recoil, ionization, 0103 physical sciences, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], 010306 general physics, scintillation counter, S030DP5, 010308 nuclear & particles physics, down: mass, sensitivity, Dark matter, Particle dark matter, Weakly interacting massive particles, Automatic Keywords, chemistry, Elementary Particles and Fields, bremsstrahlung: emission, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

Direct dark matter detection experiments based on a liquid xenon target are leading the search for dark matter particles with masses above ∼5 GeV/c2, but have limited sensitivity to lighter masses because of the small momentum transfer in dark matter-nucleus elastic scattering. However, there is an irreducible contribution from inelastic processes accompanying the elastic scattering, which leads to the excitation and ionization of the recoiling atom (the Migdal effect) or the emission of a bremsstrahlung photon. In this Letter, we report on a probe of low-mass dark matter with masses down to about 85 MeV/c2 by looking for electronic recoils induced by the Migdal effect and bremsstrahlung using data from the XENON1T experiment. Besides the approach of detecting both scintillation and ionization signals, we exploit an approach that uses ionization signals only, which allows for a lower detection threshold. This analysis significantly enhances the sensitivity of XENON1T to light dark matter previously beyond its reach.

Published
2019

21. Dielectric function and plasmonic behavior of Ga(II) and Ga(III)

Author

April S. Brown, Marta Sainz de la Maza, Pablo García-Fernández, Francisco González, Javier Junquera, Fernando Moreno, Yael Gutiérrez, Maria Losurdo, Henry O. Everitt, and Universidad de Cantabria

Subjects
Materials science, Atmospheric pressure, Surface plasmon, Physics::Optics, chemistry.chemical_element, 02 engineering and technology, Crystal structure, 021001 nanoscience & nanotechnology, 01 natural sciences, Electronic, Optical and Magnetic Materials, 010309 optics, chemistry, Chemical physics, Metastability, 0103 physical sciences, Gallium, Thin film, 0210 nano-technology, Electronic band structure, Plasmon
Abstract

In order to exploit gallium’s (Ga) rich polymorphism in the design of phase-change plasmonic systems, accurate understanding of the dielectric function of the different Ga-phases is crucial. The dielectric dispersion profiles of those phases appearing at atmospheric pressure have been reported in the literature, but there is no information on the dielectric function of the high-pressure Ga-phases. Through first principles calculations we present a comprehensive analysis of the interdependence of the crystal structure, band structure, and dielectric function of two high-pressure Ga phases (Ga(II) and Ga(III)). The plasmonic behavior of these high-pressure Ga-phases is compared to those stable (liquid- and α-Ga) and metastable (β-, γ- and δ-Ga) at atmospherics pressure. This analysis can have important implications in the design of pressure-driven phase-change Ga plasmonic devices and high-pressure SERS substrates. European Commission (GA692034); Army Research Laboratory (W911NF-17-2-0023); Ministerio de Economía, Industria y Competitividad, Gobierno de España (PGC2018-096955-B-C41); Ramón y Cajal Grant (RyC-2013-12515); SODERCAN through the Research Vice-rectorate of the Universidad de Cantabria (4JU2864661). M.L. acknowledges the support of the European Commission under the H2020 grant TWINFUSYON (GA692034). Y.G. and F.M. acknowledges the support by the Army Research Laboratory under Cooperative Agreement Number W911NF-17-2-0023 and by SODERCAN (Sociedad para el Desarrollo de Cantabria) and the Research Vicerrectorate of the University of Cantabria through project 4JU2864661. Y.G. thanks the University of Cantabria for her FPU grant. P.G.-F. and J.J. acknowledge financial support from the Spanish Ministry of Economy and Competitiveness through grant number PGC2018-096955-B-C41, and P.G.-F. acknowledges support from Ramón y Cajal grant no. RyC-2013-12515.

Published
2019

22. Understanding Electromagnetic Interactions and Electron Transfer in Ga Nanoparticle–Graphene–Metal Substrate Sandwich Systems

Author

April S. Brown, Yael Gutiérrez, Maria Losurdo, Maria M. Giangregorio, and Fernando Moreno

Subjects
gallium nanoparticles, Materials science, Nanoparticle, Nanotechnology, 02 engineering and technology, engineering.material, 010402 general chemistry, 01 natural sciences, lcsh:Technology, plasmonics, law.invention, Contact angle, lcsh:Chemistry, symbols.namesake, nickel, law, General Materials Science, Work function, Surface plasmon resonance, Instrumentation, lcsh:QH301-705.5, Plasmon, Fluid Flow and Transfer Processes, Graphene, lcsh:T, Process Chemistry and Technology, graphene, General Engineering, 021001 nanoscience & nanotechnology, lcsh:QC1-999, 0104 chemical sciences, Computer Science Applications, lcsh:Biology (General), lcsh:QD1-999, lcsh:TA1-2040, copper, engineering, symbols, Noble metal, 0210 nano-technology, Raman spectroscopy, lcsh:Engineering (General). Civil engineering (General), lcsh:Physics
Abstract

Plasmonic metal nanoparticle (NP)&ndash, graphene (G) systems are of great interest due their potential role in applications as surface-enhanced spectroscopies, enhanced photodetection, and photocatalysis. Most of these studies have been performed using noble metal NPs of silver and gold. However, recent studies have demonstrated that the noble metal&ndash, graphene interaction leads to strong distortions of the graphene sheet. In order to overcome this issue, we propose the use of Ga NPs that, due to their weak interaction with graphene, do not produce any deformation of the graphene layers. Here, we analyze systems consisting of Ga NP/G/metal sandwich coupling structures, with the metal substrate being, specifically, copper (Cu) and nickel (Ni), i.e., Ga NP/G/Cu and Ga NPs/G/Ni. We experimentally show through real-time plasmonic spectroscopic ellipsometry and Raman spectroscopy measurements of the quenching of the Ga NP localized surface plasmon resonance (LSPR) depending on the wetting of the graphene by the Ga NPs and on the electron transfer through graphene. Theoretical finite-difference time-domain (FDTD) simulations supportively demonstrate that the LSPR in such sandwich structures strongly depends on the contact angle of the NP with graphene. Finally, we also provide evidence of the electron transfer from the Ga NPs into the graphene and into the metal substrate according to the work function alignments. These considerations about the contact angle and, consequently, geometry and wetting of the metal NPs on graphene, are useful to guide the design of those plasmonic systems to maximize electromagnetic enhancement.

Published
2019

23. Structural Characterization of the Nanocolumnar Microstructure of InAlN

Author

Kristen Collar, Tong-Ho Kim, Wei Kong, J. H. Leach, April S. Brown, Junfei Li, Wenyuan Jiao, and John H. Fournelle

Subjects
010302 applied physics, Diffraction, Materials science, business.industry, Nanotechnology, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Microstructure, 01 natural sciences, Electronic, Optical and Magnetic Materials, Semiconductor, Transmission electron microscopy, 0103 physical sciences, X-ray crystallography, Microscopy, Materials Chemistry, Optoelectronics, Electrical and Electronic Engineering, Thin film, 0210 nano-technology, business, Molecular beam epitaxy
Abstract

In x Al(1−x)N (InAlN) thin films, lattice-matched to GaN with an In composition of ∼17%, are of interest for GaN-based devices. However, InAlN thin films grown by molecular beam epitaxy exhibit a characteristic lateral composition modulation, or nanocolumnar microstructure, with an Al-rich center region and an In-rich boundary. The mechanism driving the formation of this microstructure remains unknown. To date, the structural characterization of the nanocolumn domain size and its associated compositional variation is challenging, requiring either transmission electron microscopy or atomic probe microscopy. We show that the nanocolumnar microstructure can be characterized using x-ray diffraction and is associated with increased diffuse scattering. Using this technique, we show that the development of the microstructure is dependent on growth temperature.

Published
2015

25. Multiphase Gallium-based Nanoparticles for a Versatile Plasmonic Platform

Author

April S. Brown, Josef Humlíček, Maria Losurdo, Fernando Moreno, Yael Gutiérrez, and Maria M. Giangregorio

Subjects
010302 applied physics, Materials science, business.industry, Infrared, Physics::Optics, Nanoparticle, chemistry.chemical_element, Polarization (waves), 01 natural sciences, 7. Clean energy, chemistry, 0103 physical sciences, Solid phases, Optoelectronics, Symmetry breaking, Surface plasmon resonance, Gallium, 010306 general physics, business, Plasmon
Abstract

Gallium nanoparticles have been deposited on various substrates of technological interest. The interaction with the substrate leads to two plasmon resonance modes that can be tuned from the UV to the visible and infrared. Large polarization-dependent splitting of plasmon resonance modes arises from the broken symmetry of hemispherical gallium nanoparticles on substrates; this splitting depends on interaction with the substrate, on the angle of illumination and on the polarization state of light. These splitting plasmon modes are also dependent on the liquid and solid phases of gallium.

Published
2018

26. Observation of coherent elastic neutrino-nucleus scattering

Author

S. Ki, M. Hai, C. Leadbetter, G. Perumpilly, Seppo Penttila, Belkis Cabrera-Palmer, N. Fields, Alexander Bolozdynya, W. Fox, Erik B. Iverson, C.-H. Yu, Bjorn Scholz, R. L. Varner, J. Raybern, S. R. Elliott, S. R. Klein, M. P. Green, J. A. Detwiler, Jason Newby, Yuri Efremenko, C. J. Virtue, G.C. Rich, John L. Orrell, Lorenzo Fabris, Jaeun Yoo, L. J. Kaufman, D. M. Markoff, Kathryn Mann, B. Becker, Michael Febbraro, A. V. Kumpan, B. Suh, A. Eberhardt, P. E. Mueller, Robert Cooper, D. Rudik, Z. Fu, H. Moreno, P. An, J. Vanderwerp, David Reyna, C. Cuesta, Z. Wan, R. Tayloe, A. Konovalov, Liang Li, Kate Scholberg, G. Sinev, Todd W. Hossbach, A. Shakirov, A.V. Khromov, A. Zawada, April S. Brown, D. Hornback, J. Zettlemoyer, S. Hedges, V.V. Sosnovtsev, Reynold J. Cooper, Justin Albert, A. Galindo-Uribarri, M. Cervantes, I. Tolstukhin, J. I. Collar, W. M. Snow, D. Akimov, D. J. Dean, Rod Thornton, S. Suchyta, Diana Parno, A. M. Zderic, E. M. Erkela, Cory T. Overman, W. Lu, D. Rimal, K. Miller, M. Kremer, C. Awe, M.R. Heath, P. S. Barbeau, V. A. Belov, and H. Ray

Subjects
Quark, Nuclear Theory, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Scintillator, 01 natural sciences, Standard Model, High Energy Physics - Experiment, Nuclear physics, Nuclear Theory (nucl-th), High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Elastic scattering, Physics, Multidisciplinary, 010308 nuclear & particles physics, Scattering, Detector, High Energy Physics - Phenomenology, High Energy Physics::Experiment, Neutrino, Spallation Neutron Source
Abstract

Detecting neutrinos—elementary particles that barely interact with other matter—usually requires detectors of enormous size. A particular interaction of neutrinos with atomic nuclei, called the coherent elastic neutrino-nucleus scattering (CEνNS), is predicted to occur with relatively high probability, and it could be used to drastically reduce the size of neutrino detectors. However, observing this interaction requires a source of low-energy neutrinos and detectors that contain nuclei of optimal mass. Akimov et al. observed CEνNS with a 6.7σ confidence by using a comparatively tiny, 14.6-kg sodium-doped CsI scintillator exposed to neutrinos from a spallation neutron facility (see the Perspective by Link). The discovery places tighter bounds on exotic, beyond-the-standard-model interactions involving neutrinos. Science , this issue p. [1123][1]; see also p. [1098][2] [1]: /lookup/doi/10.1126/science.aao0990 [2]: /lookup/doi/10.1126/science.aao4050

Published
2017

27. Online $$^{222}$$ 222 Rn removal by cryogenic distillation in the XENON100 experiment

Author

April S. Brown, P. Shagin, R. Itay, A. Kish, D. Mayani, Jochen Schreiner, M. P. Decowski, T. Berger, M. Anthony, D. Thers, R. F. Lang, S. Rosendahl, Manfred Lindner, M. Cervantes, M. v. Sivers, Julien Masbou, Michelle Galloway, M. Le Calloch, D. Lellouch, Laura Baudis, A. Tiseni, Yuehuan Wei, V. Pizzella, D. Cichon, S. E. A. Orrigo, C. Hasterok, Z. Greene, R. Saldanha, G. Eurin, M. L. Benabderrahmane, Ethan Brown, M. Messina, Hulin Wang, G. C. Trinchero, J. Pienaar, K. Micheneau, J. Naganoma, T. Marrodán Undagoitia, Ehud Duchovni, João Cardoso, G. Kessler, J.M.F. dos Santos, F. Gao, Elena Aprile, Jelle Aalbers, F. Arneodo, Ran Budnik, L. Levinson, Ioana Codrina Maris, F. Agostini, F. V. Massoli, Qing Lin, F. Piastra, Marc Schumann, F. D. Amaro, P. Pakarha, Sebastian Lindemann, Guillaume Plante, Giacomo Bruno, E. Hogenbirk, E. Shockley, A. Di Giovanni, Boris Bauermeister, W. Fulgione, S. Reichard, C. Reuter, M. Alfonsi, Y. Meng, M. Selvi, M. Murra, L. Rauch, J. Ye, A. Fieguth, D. Coderre, Manuel Gameiro da Silva, A. Stein, R. Persiani, B. Kaminsky, C. Tunnell, A. Molinario, Sara Diglio, M. Scheibelhut, A. Gallo Rosso, Jan Conrad, P. Barrow, Yanxi Zhang, C. Geis, J. Fei, N. Upole, A. Rizzo, N. Priel, Jean-Pierre Cussonneau, L. Bütikofer, Auke-Pieter Colijn, Bart Pelssers, Uwe Oberlack, P. Di Gangi, M. Garbini, J. A. M. Lopes A. Manfredini, C. Grignon, Kaixuan Ni, S. Schindler, D. Franco, H. Landsman, I. Cristescu, P. de Perio, D. Masson, B. Miguez, N. Rupp, L. Scotto Lavina, Hardy Simgen, A. D. Ferella, Ch. Weinheimer, P. A. Breur, G. Sartorelli, S. Bruenner, J. Wulf, M.-C. Piro, L. Grandi, Luke Goetzke, and J. Calvén

Subjects
Air separation, Materials science, Physics and Astronomy (miscellaneous), 010308 nuclear & particles physics, Detector, Analytical chemistry, chemistry.chemical_element, Noble gas, Radon, 01 natural sciences, Xenon, chemistry, Fractionating column, 0103 physical sciences, Activity concentration, 010306 general physics, Engineering (miscellaneous), Reduction factor
Abstract

We describe the purification of xenon from traces of the radioactive noble gas radon using a cryogenic distillation column. The distillation column is integrated into the gas purification loop of the XENON100 detector for online radon removal. This enabled us to significantly reduce the constant $^{222}$Rn background originating from radon emanation. After inserting an auxiliary $^{222}$Rn emanation source in the gas loop, we determined a radon reduction factor of R > 27 (95% C.L.) for the distillation column by monitoring the $^{222}$Rn activity concentration inside the XENON100 detector.

Published
2017

28. Erratum: Low-mass dark matter search using ionization signals in XENON100 [Phys. Rev. D 94 , 092001 (2016)]

Author

Y. Meng, P. de Perio, D. Cichon, U. Oberlack, T. Berger, S. Rosendahl, T. Marrodán Undagoitia, J. Pienaar, K. Micheneau, Jelle Aalbers, D. Franco, P. A. Breur, B. Kaminsky, Elena Aprile, G. Sartorelli, Michelle Galloway, C. Grignon, April S. Brown, M. P. Decowski, A. Manfredini, R. Itay, B. Miguez, Manfred Lindner, Jochen Schreiner, P. Shagin, Hulin Wang, Laura Baudis, Matthew Anthony, M. Cervantes, D. Thers, M. L. Benabderrahmane, Ethan Brown, A. Tiseni, C. Hasterok, A. Kish, M. Weber, Yuehuan Wei, D. Mayani, F. D. Amaro, A. Buss, E. Hogenbirk, L. Scotto Lavina, F. Arneodo, M. Le Calloch, Hardy Simgen, Lorne Levinson, R. Persiani, Guillaume Plante, A. D. Ferella, G. Kessler, P. Barrow, C. Weinheimer, C. Reuter, Z. Greene, Giacomo Bruno, M. Selvi, A. Fieguth, D. Coderre, S. Schindler, Boris Bauermeister, R. Wall, Luke Goetzke, S. E. A. Orrigo, E. K. U. Gross, C. Geis, A. Rizzo, P. Di Gangi, L. Rauch, N. Rupp, M. Scheibelhut, João Cardoso, S. Bruenner, J. Wulf, H. Landsman, C. Tunnell, R. Budnik, J. Naganoma, Jean-Pierre Cussonneau, D. Masson, Lukas Bütikofer, Ehud Duchovni, Marc Schumann, A. J. Melgarejo Fernandez, A. Lyashenko, Julien Masbou, M. Alfonsi, A. Stein, Bart Pelssers, R. F. Lang, A. P. Colijn, G. C. Trinchero, J.M.F. dos Santos, F. Agostini, M. von Sivers, A. Di Giovanni, M. Garbini, Sebastian Lindemann, F. V. Massoli, M. Murra, Payam Pakarha, N. Priel, S. Reichard, A. Molinario, Y. Zhang, F. L. Linde, C. Levy, F. Piastra, M. Messina, J.A.M. Lopes, W. Fulgione, and Jan Conrad

Subjects
Physics, 010308 nuclear & particles physics, Yield (chemistry), Ionization, 0103 physical sciences, Dark matter, Charge (physics), Atomic physics, 010306 general physics, Low Mass, 01 natural sciences
Abstract

In Fig. 5 of our original article, we compared measurements and predictions of the charge yield Qy. In that figure, the LUX points were misrepresented, and therefore we present here in Fig. 1 the corrected points from Ref. [1].

Published
2017

29. Erratum: First axion results from the XENON100 experiment [Phys. Rev. D 90 , 062009 (2014)]

Author

H. Landsman, Daniel Lellouch, F. Piastra, S. Schindler, B. Miguez, L. Scotto Lavina, M. Selvi, M. Auger, Hardy Simgen, A. D. Ferella, Hulin Wang, C. Levy, Kaixuan Ni, D. Mayani Paras, M. Messina, K. Arisaka, G. Kessler, P. Shagin, N. Priel, A. Kish, J. Naganoma, F. Arneodo, H. Contreras, J.A.M. Lopes, C. Balan, Marc Schumann, Y. Meng, Ethan Brown, S. Reichard, W. Fulgione, M. P. Decowski, U. Oberlack, Manfred Lindner, O. Vitells, C. Geis, A. Rizzo, C. Grignon, A. Tiseni, A. Molinario, Giacomo Bruno, S. Macmullin, Florian Kaether, T. Marrodán Undagoitia, S. Bruenner, Gabriella Sartorelli, R. F. Lang, C. Weinheimer, A. P. Colijn, D. Thers, M. Weber, Guillaume Plante, Boris Bauermeister, W. Hampel, M. Garbini, April S. Brown, R. Itay, Jochen Schreiner, F. V. Massoli, M. Le Calloch, C. Reuter, S. E. A. Orrigo, Elena Aprile, João Cardoso, F. Gao, S. Rosendahl, J.M.F. dos Santos, F. Agostini, Sebastian Lindemann, E. Pantic, R. Budnik, Luke Goetzke, S. Fattori, G. C. Trinchero, A. J. Melgarejo Fernandez, M. Murra, Jean-Pierre Cussonneau, M. Alfonsi, K. Lung, Laura Baudis, J. Pienaar, P. Beltrame, Ehud Duchovni, A. Behrens, A. Lyashenko, A. Teymourian, P. Barrow, K. Bokeloh, E. K. U. Gross, R. Persiani, Julien Masbou, Aprile, E., Agostini, F., Alfonsi, M., Arisaka, K., Arneodo, F., Auger, M., Balan, C., Barrow, P., Baudis, L., Bauermeister, B., Behrens, A., Beltrame, P., Bokeloh, K., Brown, A., Brown, E., Bruenner, S., Bruno, G., Budnik, R., Cardoso, J. m. r., Colijn, A. p., Contreras, H., Cussonneau, J. p., Decowski, M. p., Duchovni, E., Fattori, S., Ferella, A. d., Fulgione, W., Gao, F., Garbini, M., Geis, C., Goetzke, L. w., Grignon, C., Gross, E., Hampel, W., Itay, R., Kaether, F., Kessler, G., Kish, A., Landsman, H., Lang, R. f., Le Calloch, M., Lellouch, D., Levy, C., Lindemann, S., Lindner, M., Lopes, J. a. m., Lung, K., Lyashenko, A., Macmullin, S., Marrodán Undagoitia, T., Masbou, J., Massoli, F. v., Mayani Paras, D., Melgarejo Fernandez, A. j., Meng, Y., Messina, M., Miguez, B., Molinario, A., Murra, M., Naganoma, J., Ni, K., Oberlack, U., Orrigo, S. e. a., Pantic, E., Persiani, R., Piastra, F., Pienaar, J., Plante, G., Priel, N., Reichard, S., Reuter, C., Rizzo, A., Rosendahl, S., dos Santos, J. m. f., Sartorelli, G., Schindler, S., Schreiner, J., Schumann, M., Scotto Lavina, L., Selvi, M., Shagin, P., Simgen, H., Teymourian, A., Thers, D., Tiseni, A., Trinchero, G., Vitells, O., Wang, H., Weber, M., and Weinheimer, C.

Subjects
Physics, Particle physics, XENON DARK MATTER AXION, 010308 nuclear & particles physics, 0103 physical sciences, Limit (mathematics), 010306 general physics, Coupling (probability), 01 natural sciences, Axion
Abstract

n our paper, we presented searches for solar axions and galactic axionlike particles (ALPs) in the data collected by the XENON100 experiment (with an exposure of 224.6 days). We recently found a bug in the code to calculate the exclusion limit for galactic ALPs. This resulted in an underestimation of the ALP expected rate, which in turn led to an overly conservative limit, compared to what it should really be. We corrected the code, and the result of the XENON100 90% C.L. exclusion limit on galactic ALPs (shown in Fig. 1) was reevaluated. The corrected limit is stronger than the one previously published by approximately a factor of 5 across all masses and sets the best published limit on the axion-electron coupling, $g_{Ae}$, in the (1–40) keV/$c^2$ mass range.

Published
2017

30. Effective field theory search for high-energy nuclear recoils using the XENON100 dark matter detector

Author

Sara Diglio, F. V. Massoli, Qing Lin, J. Calvén, Ch. Weinheimer, Marc Schumann, P. Pakarha, W. Fulgione, J. Ye, A. Manfredini, M. Murra, Ben Farmer, Luke Goetzke, M. V. Sivers, Jean-Pierre Cussonneau, F. Lombardi, M.-C. Piro, L. Buetikofer, J.M.F. dos Santos, D. Masson, Bart Pelssers, C. Geis, C. Hasterok, C. Reuter, M. Messina, F. Agostini, M. L. Benabderrahmane, A. Rizzo, P. Di Gangi, P. de Perio, B. Kaminsky, Ethan Brown, Julien Masbou, Teresa Marrodán Undagoitia, Sebastian Lindemann, H. Simgen, L. Scotto Lavina, Yanxi Zhang, Yuehuan Wei, K. Morå, Zhou Wang, C. Tunnell, A. Di Giovanni, A. D. Ferella, M. Selvi, G. Eurin, Kaixuan Ni, Hongwei Wang, Giacomo Bruno, Gabriella Sartorelli, Uwe Oberlack, J. A. M. Lopes, A. Kish, L. Levinson, J. Pienaar, M. Garbini, Ioana Codrina Maris, V. Pizzella, C. Grignon, April S. Brown, K. Micheneau, R. Itay, G. Kessler, M. Alfonsi, S. Bruenner, J. Wulf, Laura Baudis, J. Naganoma, Jelle Aalbers, Z. Greene, J. Schreiner, Ran Budnik, M. P. Decowski, M. Vargas, Auke-Pieter Colijn, P. A. Breur, Manfred Lindner, F. D. Amaro, Guillaume Plante, A. Stein, M. Cervantes, R. Persiani, D. Cichon, P. Barrow, D. Lellouch, A. Fieguth, D. Coderre, Boris Bauermeister, Manuel Gameiro da Silva, F. Arneodo, A. Tiseni, J. Fei, A. Molinario, M. Scheibelhut, João Cardoso, Elena Aprile, F. Gao, Gian Carlo Trinchero, S. Schindler, N. Rupp, S. Reichard, F. Piastra, T. Berger, S. Rosendahl, N. Priel, Shingo Kazama, Jan Conrad, M. Anthony, R. F. Lang, E. Hogenbirk, P. Shagin, D. Mayani, Dominique Thers, L. Rauch, H. Landsman, A. Gallo Rosso, A. Di Galloway, Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), XENON, Laboratoire de physique subatomique et des technologies associées ( SUBATECH ), IMT Atlantique Bretagne-Pays de la Loire ( IMT Atlantique ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Nantes ( UN ), Laboratoire de Physique Nucléaire et de Hautes Énergies ( LPNHE ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS ), Aprile, E., Aalbers, J., Agostini, F., Alfonsi, M., Amaro, F.D., Anthony, M., Arneodo, F., Barrow, P., Baudis, L., Bauermeister, B., Benabderrahmane, M.L., Berger, T., Breur, P.A., Brown, A., Brown, E., Bruenner, S., Bruno, G., Budnik, R., Bütikofer, L., Calvén, J., Cardoso, J.M.R., Cervantes, M., Cichon, D., Coderre, D., Colijn, A.P., Conrad, J., Cussonneau, J.P., Decowski, M.P., De Perio, P., Di Gangi, P., Di Giovanni, A., Diglio, S., Eurin, G., Fei, J., Ferella, A.D., Fieguth, A., Fulgione, W., Gallo Rosso, A., Galloway, M., Gao, F., Garbini, M., Geis, C., Goetzke, L.W., Greene, Z., Grignon, C., Hasterok, C., Hogenbirk, E., Itay, R., Kaminsky, B., Kazama, S., Kessler, G., Kish, A., Landsman, H., Lang, R.F., Lellouch, D., Levinson, L., Lin, Q., Lindemann, S., Lindner, M., Lombardi, F., Lopes, J.A.M., Manfredini, A., Maris, I., Marrodán Undagoitia, T., Masbou, J., Massoli, F.V., Masson, D., Mayani, D., Messina, M., Micheneau, K., Molinario, A., Morå, K., Murra, M., Naganoma, J., Ni, K., Oberlack, U., Pakarha, P., Pelssers, B., Persiani, R., Piastra, F., Pienaar, J., Pizzella, V., Piro, M.-C., Plante, G., Priel, N., Rauch, L., Reichard, S., Reuter, C., Rizzo, A., Rosendahl, S., Rupp, N., Dos Santos, J.M.F., Sartorelli, G., Scheibelhut, M., Schindler, S., Schreiner, J., Schumann, M., Scotto Lavina, L., Selvi, M., Shagin, P., Silva, M., Simgen, H., Sivers, M.V., Stein, A., Thers, D., Tiseni, A., Trinchero, G., Tunnell, C., Vargas, M., Wang, H., Wang, Z., Wei, Y., Weinheimer, C., Wulf, J., Ye, J., Farmer, B., Zhang, Y., Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), and XENON (IHEF, IoP, FNWI)

Subjects
WIMP nucleon: scattering, Particle physics, data analysis method, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Physics and Astronomy (miscellaneous), Physics::Instrumentation and Detectors, WIMP, [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph], Dark matter, chemistry.chemical_element, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Nuclear physics, XENON, Xenon, statistical analysis, 0103 physical sciences, Effective field theory, Dark Matter, 010306 general physics, S030UDM, nucleus: recoil, Physics, Coupling constant, effective field theory: nonrelativistic, 010308 nuclear & particles physics, Scattering, Detector, Astrophysics::Instrumentation and Methods for Astrophysics, dark matter: detector, chemistry, Weakly interacting massive particles, Direct Search, High Energy Physics::Experiment, TPC, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], recoil: energy, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

International audience; We report on weakly interacting massive particles (WIMPs) search results in the XENON100 detector using a nonrelativistic effective field theory approach. The data from science run II (34 kg×224.6 live days) were reanalyzed, with an increased recoil energy interval compared to previous analyses, ranging from (6.6–240) keVnr. The data are found to be compatible with the background-only hypothesis. We present 90% confidence level exclusion limits on the coupling constants of WIMP-nucleon effective operators using a binned profile likelihood method. We also consider the case of inelastic WIMP scattering, where incident WIMPs may up-scatter to a higher mass state, and set exclusion limits on this model as well.

Published
2017

31. Gallium Polymorphs: Phase‐Dependent Plasmonics

Author

Maria Losurdo, Fernando Moreno, April S. Brown, Yael Gutiérrez, Francisco González, Marta Sainz de la Maza, Pablo García-Fernández, Henry O. Everitt, and Javier Junquera

Subjects
Materials science, chemistry.chemical_element, Nanoparticle, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Phase change, chemistry, Polymorphism (materials science), Chemical physics, 0103 physical sciences, Spectroscopic ellipsometry, Dielectric function, Gallium, 010306 general physics, 0210 nano-technology, Plasmon
Published
2019

32. Optically addressing interaction of Mg/MgO plasmonic systems with hydrogen

Author

Fernando Moreno, April S. Brown, Fabio Palumbo, Maria Losurdo, Maria M. Giangregorio, Yael Gutiérrez, and Universidad de Cantabria

Subjects
Plasmonic nanoparticles, Nanostructure, Materials science, Hydrogen, business.industry, Magnesium, chemistry.chemical_element, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Atomic and Molecular Physics, and Optics, 010309 optics, symbols.namesake, Optics, chemistry, Chemical engineering, Ellipsometry, Hydrogen economy, 0103 physical sciences, symbols, Thin film, 0210 nano-technology, business, Raman spectroscopy
Abstract

Magnesium-based films and nanostructures are being studied in order to improve hydrogen reversibility, storage capacity, and kinetics, because of their potential in the hydrogen economy. Some challenges with magnesium (Mg) samples are their unavoidable oxidation by air exposure and lack of direct in situ real time measurements of hydrogen interaction with Mg and MgO surfaces and Mg plasmonic nanoparticles. Given these challenges, the present article investigates direct interaction of Mg with hydrogen, as well as implications of its inevitable oxidation by real-time spectroscopic ellipsometry for exploiting the optical properties of Mg, MgH2 and MgO. The direct hydrogenation measurements have been performed in a reactor that combines a remote hydrogen plasma source with an in situ spectroscopic ellipsometer, which allows optical monitoring of the hydrogen interaction and results in optical property modification. The hydrogen plasma dual use is to provide the hydrogen-atoms and to reduce barriers to heterogeneous hydrogen reactions. European Commission under the H2020 grant TWINFUSYON (GA692034). Army Research Laboratory under Cooperative Agreement Number W911NF-17-2-0023. SODERCAN (Sociedad para el Desarrollo de Cantabria) through the Research Vicerrectorate of the University of Cantabria.

Published
2019

33. Mixed Semiconductor Alloys for Optical Devices

Author

April S. Brown, Luke J. Mawst, and Thomas F. Kuech

Subjects
Optics and Photonics, Renewable Energy, Sustainability and the Environment, business.industry, General Chemical Engineering, Alloy, Optical communication, Heterojunction, General Chemistry, Chemical vapor deposition, Electronic structure, engineering.material, Epitaxy, Semiconductor, Semiconductors, Alloys, engineering, Optoelectronics, business, Molecular beam epitaxy
Abstract

There is an increasing technological need for a wider array of semiconducting materials that will allow greater control over the physical and electronic structure within multilayer heterostructures. This need has led to an expansion in the range of semiconducting alloys explored and used in new applications. These alloy semiconductors are often complicated by a limited range of miscibility. The current research has focused on the properties, stability, and detailed chemistry required to realize these materials. The use of synthetic conditions that permit the growth of these alloys to be dominated by kinetic rather than mass-transport considerations has allowed many of these nominally unstable materials to be grown and used in device structures. These materials have found important applications within optical communications as emitters and detectors and in solid-state lighting.

Published
2013

34. Thermally stable coexistence of liquid and solid phases in gallium nanoparticles

Author

April S. Brown, Sergey Rubanov, Kurt Hingerl, Maria Losurdo, and Alexandra Suvorova

Subjects
Range (particle radiation), Materials science, Chromatography, Mechanical Engineering, Nanoparticle, chemistry.chemical_element, 02 engineering and technology, General Chemistry, Substrate (electronics), 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Epitaxy, 01 natural sciences, 0104 chemical sciences, Chemical engineering, chemistry, Mechanics of Materials, Solid phases, General Materials Science, Laplace pressure, Gallium, 0210 nano-technology, Nanoscopic scale
Abstract

Gallium (Ga), a group III metal, is of fundamental interest due to its polymorphism and unusual phase transition behaviours. New solid phases have been observed when Ga is confined at the nanoscale. Herein, we demonstrate the stable coexistence, from 180 K to 800 K, of the unexpected solid γ-phase core and a liquid shell in substrate-supported Ga nanoparticles. We show that the support plays a fundamental role in determining Ga nanoparticle phases, with the driving forces for the nucleation of the γ-phase being the Laplace pressure in the nanoparticles and the epitaxial relationship of this phase to the substrate. We exploit the change in the amplitude of the evolving surface plasmon resonance of Ga nanoparticle ensembles during synthesis to reveal in real time the solid core formation in the liquid Ga nanoparticle. Finally, we provide a general framework for understanding how nanoscale confinement, interfacial and surface energies, and crystalline relationships to the substrate enable and stabilize the coexistence of unexpected phases.

Published
2016

35. Chemical Characterization of DNA-Immobilized InAs Surfaces Using X-ray Photoelectron Spectroscopy and Near-Edge X-ray Absorption Fine Structure

Author

EunKyung Cho, Thomas F. Kuech, and April S. Brown

Subjects
Materials science, Surface Properties, Analytical chemistry, Oxide, DNA, Single-Stranded, Indium, Molecular physics, Arsenicals, chemistry.chemical_compound, X-ray photoelectron spectroscopy, Electrochemistry, General Materials Science, Spectroscopy, Aqueous solution, Base Sequence, Photoelectron Spectroscopy, Oxides, Surfaces and Interfaces, Condensed Matter Physics, XANES, X-ray absorption fine structure, Chemical state, X-Ray Absorption Spectroscopy, chemistry, Surface modification, Absorption (chemistry), DNA Probes
Abstract

Single-stranded DNA immobilized on an III-V semiconductor is a potential high-sensitivity biosensor. The chemical and electronic changes occurring upon the binding of DNA to the InAs surface are essential to understanding the DNA-immobilization mechanism. In this work, the chemical properties of DNA-immobilized InAs surfaces were determined through high-resolution X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS). Prior to DNA functionalization, HF- and NH(4)OH- based aqueous etches were used to remove the native oxide from the InAs surface. The initial chemical state of the surface resulting from these etches were characterized prior to functionalization. F-tagged thiolated single-stranded DNA (ssDNA) was used as the probe species under two different functionalization methods. The presence of DNA immobilized on the surface was confirmed from the F 1s, N 1s, and P 2p peaks in the XPS spectra. The presence of salt had a profound effect on the density of immobilized DNA on the InAs surface. To study the interfacial chemistry, the surface was treated with thiolated ssDNA with and without the mercaptohexanol molecule. An analysis of the As 3d and In 3d spectra indicates that both In-S and As-S are present on the surface after DNA functionalization. The amount of In-S and As-S was determined by the functionalization method as well as the presence of mercaptohexanol during functionalization. The orientation of the adsorbed ssDNA is determined by polarization-dependent NEXAFS utilizing the N K-edge. The immobilized ssDNA molecule has a preferred tilt angle with respect to the substrate normal, but with a random azimuthal distribution.

Published
2012

36. Plasma-plasmonics synergy in the Ga-catalyzed growth of Si-nanowires

Author

Giovanni Bruno, April S. Brown, Pio Capezzuto, Tong-Ho Kim, Maria M. Giangregorio, Maria Losurdo, and Giuseppe Valerio Bianco

Subjects
Materials science, Hydrogen, Hydride, Mechanical Engineering, Plasma activation, Oxide, Analytical chemistry, Nanowire, chemistry.chemical_element, Condensed Matter Physics, Catalysis, chemistry.chemical_compound, chemistry, Chemical engineering, Mechanics of Materials, General Materials Science, Gallium, Dissolution
Abstract

This paper reports on the growth of Si nanowires (NWs) by SiH 4 /H 2 plasmas using the non-noble Ga-nanoparticles (NPs) catalysts. A comparative investigation of conventional Si-NWs vapour–liquid–solid (VLS) growth catalyzed by Au NPs is also reported. We investigate the use of a hydrogen plasma and of a SiH 4 /H 2 plasma for removing Ga oxide shell and for enhancing the Si dissolution into the catalyst, respectively. By exploiting the Ga NPs surface plasmon resonance (SPR) sensitivity to their surface chemistry, the SPR characteristic of Ga NPs has been monitored by real time spectroscopic ellipsometry in order to control the hydrogen plasma/Ga NPs interaction and the involved processes (oxide removal and NPs dissolution by volatile gallium hydride). Using in situ laser reflectance interferometry the metal catalyzed Si NWs growth process has been investigated to find the effect of the plasma activation on the growth kinetics. The role of atomic hydrogen in the NWs growth mechanism and, in particular, in the SiH 4 dissolution into the catalysts, is discussed. We show that while Au catalysts because of the re-aggregation of NPs yields NWs that do not correspond to the original size of the Au NPs catalyst, the NWs grown by the Ga catalyst retains the diameter dictated by the size of the Ga NPs. Therefore, the advantage of Ga NPs as catalysts for controlling NWs diameter is demonstrated.

Published
2012

37. Quality of Warfarin Anticoagulation for Atrial Fibrillation in Indigenous and Non-Indigenous Australians

Author

Transon V. Nguyen, P. Sanders, Melissa E. Middeldorp, Rajiv Mahajan, Christopher X. Wong, April S. Brown, Jeroen M.L. Hendriks, S. Rocheleau, Stephen J. Nicholls, Celine Gallagher, and Dennis H. Lau

Subjects
Pulmonary and Respiratory Medicine, medicine.medical_specialty, business.industry, media_common.quotation_subject, 05 social sciences, Warfarin, Atrial fibrillation, 030204 cardiovascular system & hematology, medicine.disease, Indigenous, 03 medical and health sciences, 0302 clinical medicine, Internal medicine, 0502 economics and business, Cardiology, Medicine, 050211 marketing, Quality (business), Cardiology and Cardiovascular Medicine, business, Intensive care medicine, medicine.drug, media_common
Published
2017

38. Hemin-Functionalized InAs-Based High Sensitivity Room Temperature NO Gas Sensors

Author

Peter A. Torrione, Aruna Dedigama, Giovanni Bruno, Michael Angelo, Thomas F. Kuech, Tong-Ho Kim, Scott D. Wolter, Madhavie Edirisoorya, Leslie M. Collins, April S. Brown, William V. Lampert, Maria Losurdo, and Ayomide Atewologun

Subjects
Materials science, Kinetics, equipment and supplies, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, law.invention, chemistry.chemical_compound, General Energy, Planar, chemistry, Chemical engineering, law, polycyclic compounds, Surface modification, heterocyclic compounds, Sensitivity (control systems), Physical and Theoretical Chemistry, Resistor, Hemin
Abstract

We investigate the chemistry and kinetics of the surface functionalization of InAs with hemin aimed at demonstrating novel hemin-functionalized InAs planar resistors or molecularly controlled resistors (MOCSERs) with subparts per billion sensitivity to NO at 300 K. The high performance is a result of the strong coupling of the intrinsic surface-confined two-dimensional electron gas (2DEG) at the InAs surface with the surface-attached hemin molecules and their selective interactions with NO. The presence of the surface 2DEG in InAs is highly advantageous for sensing and obviates the need for high surface area to volume geometries conferred by nanowire structures. The chemistry and kinetics of surface attachment processes are investigated using X-ray photoelectron spectroscopy, atomic force microscopy, and spectroscopic ellipsometry, showing that the covalent attachment of hemin to both In and As sites modifies the band-bending of the InAs. In addition, the selective, reversible electronic interaction between hemin and NO molecules increases the InAs resistance, reducing the NO during the interaction. In addition to presenting the sensor performance characteristics, a chemical model based on the electron transfer from the 2DEG of InAs to the iron center of hemin, which reduces Fe(III) to the higher NO affinity Fe(II) state, is proposed.

Published
2011

39. Ga–Mg Core–Shell Nanosystem for a Novel Full Color Plasmonics

Author

Fernando Moreno, Pae C. Wu, Tong-Ho Kim, Giovanni Bruno, April S. Brown, Borja Garcia-Cueto, and Maria Losurdo

Subjects
Materials science, Physics::Optics, Nanoparticle, chemistry.chemical_element, Resonance, Nanotechnology, Substrate (electronics), Discrete dipole approximation, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Nanomaterials, General Energy, chemistry, Physics::Atomic and Molecular Clusters, Physical and Theoretical Chemistry, Gallium, Surface plasmon resonance, Plasmon
Abstract

Gallium–magnesium (Ga–Mg) core–shell nanoparticles were synthesized by sequential evaporation of gallium and magnesium molecular beams on sapphire substrates. The surface plasmon resonance properties of this novel bimetallic system are demonstrated and investigated in a broad spectral range, from the near-UV to the visible and to the near-IR by in situ real-time spectroscopic ellipsometry. Both the mean NP ensemble diameter and the relative core–shell radii affect the resultant plasmon resonance, and this study shows that the resonance can be red-shifted and tuned into the near-IR by increasing the extent of the Mg-shell, while limiting the overall nanoparticle size, promoting this novel, nanomaterials system for applications of bifunctional plasmonic-catalytic nanoparticles with optical properties tunable across a broad spectral range. Experimental real-time plasmonic results are corroborated by discrete dipole approximation calculations applied to core–shell nanoparticles supported on the substrate, whi...

Published
2011

40. GaMg Alloy Nanoparticles for Broadly Tunable Plasmonics

Author

April S. Brown, Maria Losurdo, Alexandra Suvorova, Martin Saunders, Maria M. Giangregorio, Tong-Ho Kim, Pae C. Wu, and Giovanni Bruno

Subjects
Materials science, Metallic nanostructures, Alloy, Metal Nanoparticles, Nanoparticle, Gallium, Nanotechnology, 02 engineering and technology, engineering.material, 010402 general chemistry, 01 natural sciences, Nanomaterials, Biomaterials, Optics, Alloys, Magnesium, General Materials Science, Nanoscopic scale, Plasmon, business.industry, General Chemistry, Surface Plasmon Resonance, 021001 nanoscience & nanotechnology, Plasmonic metamaterials, 0104 chemical sciences, engineering, 0210 nano-technology, business, Biotechnology
Abstract

Manipulating the properties of well understood materials systems for novel technological applications can be achieved by creating nanoscale structures and mixed compounds. The design of novel nanomaterials that underpin plasmonic applications drives the rapid progress in advancing plasmonic materials over the last few years. [ 1 , 2 ] Control of metal nanoparticle shape, [ 3 , 4 ] density, and spacing [ 5 ] is continually improving with novel synthetic techniques. Nevertheless, to continue advancing plasmonics, new metallic nanostructure systems must be developed that offer unique properties and are superior to Ag, [ 6 ] Au, [ 3 , 7 ] and mixtures thereof—the most widely exploited metals [ 8–10 ] and bimetallic systems. [ 11 ]

Published
2011

44. Unidirectional lateral nanowire formation during the epitaxial growth of GaAsBi on vicinal substrates

Author

Wei Kong, Jincheng Li, Wenyuan Jiao, April S. Brown, and Kristen Collar

Subjects
010302 applied physics, Nanostructure, Materials science, Misorientation, business.industry, Mechanical Engineering, Nanowire, Bioengineering, 02 engineering and technology, General Chemistry, 021001 nanoscience & nanotechnology, Epitaxy, 01 natural sciences, Diffusion Anisotropy, Mechanics of Materials, 0103 physical sciences, Optoelectronics, General Materials Science, Electrical and Electronic Engineering, Thin film, 0210 nano-technology, business, Anisotropy, Vicinal
Abstract

We report on enhanced control of the growth of lateral GaAs nanowires (NWs) embedded in epitaxial (100) GaAsBi thin films enabled by the use of vicinal substrates and the growth-condition dependent role of Bi as a surfactant. Enhanced step-flow growth is achieved through the use of vicinal substrates and yields unidirectional nanowire growth. The addition of Bi during GaAsBi growth enhances Ga adatom diffusion anisotropy and modifies incorporation rates at steps in comparison to GaAs growth yielding lower density but longer NWs. The NWs grown on vicinal substrates grew unidirectionally towards the misorientation direction when Bi was present. The III/V flux ratio significantly impacts the size, shape and density of the resulting NWs. These results suggest that utilizing growth conditions which enhance step-flow growth enable enhanced control of lateral nanostructures.

Published
2017

45. Tuning in to RF MEMS

Author

Mohamed El-Tanani, Kamran Entesari, Gabriel M. Rebeiz, I. Reines, A. Grichener, April S. Brown, and Sang-June Park

Subjects
Microelectromechanical systems, Radiation, business.industry, Computer science, Electrical engineering, Impedance matching, X band, High-electron-mobility transistor, Condensed Matter Physics, Electronic engineering, Radio frequency, Electrical and Electronic Engineering, business, Microwave, Diode, Voltage
Abstract

RF MEMS technology was initially developed as a replacement for GaAs HEMT switches and p-i-n diodes for low-loss switching networks and X-band to mm-wave phase shifters. However, we have found that its very low loss properties (high device Q), its simple microwave circuit model and zero power consumption, its high power (voltage/current) handling capabilities, and its very low distortion properties, all make it the ideal tuning device for reconfigurable filters, antennas and impedance matching networks. In fact, reconfigurable networks are currently being funded at the same level-if not higher-than RF MEMS phase shifters, and in our opinion, are much more challenging for high-Q designs.

Published
2009

46. Interfacial chemistry and energy band line-up of pentacene with the GaN (0001) surface

Author

J. Uhlrich, Scott D. Wolter, Thomas F. Kuech, Michael A. Garcia, and April S. Brown

Subjects
Chemistry, Analytical chemistry, Electronic structure, Condensed Matter Physics, Band offset, Inorganic Chemistry, Pentacene, chemistry.chemical_compound, Adsorption, X-ray photoelectron spectroscopy, Materials Chemistry, Surface modification, Field-effect transistor, Electronic band structure
Abstract

The chemical nature of the GaN surface combined with the bulk and surface electronic structure opens new potential application areas for this material. The nature of specific organic-GaN was developed for two cases in which the surface electronic structure of such interfaces was developed and utilized. The band alignment between n-GaN and pentacene was determined for surfaces prepared through reaction with HCl. The energy band offset was estimated through combined X-ray photoelectron spectroscopy and ultraviolet photoemission measurements. XPS measurements indicated that there was no interfacial chemical reaction. The measured valence band offset between the n-GaN and the vapor-deposited pentacene was estimated to be greater than 2 eV providing a favorable band-offset for hole-injection from the GaN layer into pentacene. The surface of a AlGaN/GaN heterojunction field effect transistor (HFET) structures was also functionalized by an adsorbed hemin layer and was shown to be sensitive to the presence of reactive species such as NO. The HFET structure provides enhanced sensitivity to changes in the surface electric field, altered through the adsorption of chemically active species either directly on the surface or through the interactions with surface functionalization.

Published
2007

47. First-principles studies on molecular beam epitaxy growth ofGaAs1−xBix

Author

M. Arjmand, Dane Morgan, April S. Brown, Thomas F. Kuech, Jincheng Li, Guangfu Luo, Izabela Szlufarska, and Shujiang Yang

Subjects
Adsorption, Materials science, Chemical physics, Diffusion, Atom, Molecule, Density functional theory, Nanotechnology, Substrate (electronics), Condensed Matter Physics, Layer (electronics), Electronic, Optical and Magnetic Materials, Molecular beam epitaxy
Abstract

We investigate the molecular beam epitaxy (MBE) growth of GaAs1-xBix film using density functional theory with spin-orbit coupling to understand the growth of this film, especially the mechanisms of Bi incorporation. We study the stable adsorption structures and kinetics of the incident molecules (As₂ molecule, Ga atom, Bi atom, and Bi₂ molecule) on the (2 x 1)-Gasub||Bi surface and a proposed q(1 x 1)-Gasub||AsAs surface has a quasi-(1 x 1) As layer above the Ga-terminated GaAs substrate and a randomly oriented As dimer layer on top. We obtain the desorption and diffusion barriers of the adsorbed molecules and also the reaction barriers of three key processes related to Bi evolution, namely, Bi incorporation, As/Bi exchange, and Bi clustering. The results help explain the experimentally observed dependence of Bi incorporation on the As/Ga ratio and growth temperature. Furthermore, we find that As₂ exchange with Bi of the (2 x 1)-Gasub||Bi surface is a key step controlling the kinetics of the Bi incorporation. Finally, we explore two possible methods to enhance the Bi incorporation, namely, replacing the MBE growth mode from codeposition of all fluxes with a sequential deposition of fluxes and applying asymmetric in-plane strain to the substrate.

Published
2015

48. Insights into the effects of metal nanostructuring and oxidation on the work function and charge transfer of metal/graphene hybrids

Author

Maria Losurdo, Pio Capezzuto, April S. Brown, Giovanni Bruno, Giuseppe Valerio Bianco, Maria M. Giangregorio, and Wenyuan Jiao

Subjects
Kelvin probe force microscope, Materials science, Nanostructure, Graphene, Doping, Nanotechnology, Heterojunction, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, law.invention, Metal, law, visual_art, visual_art.visual_art_medium, General Materials Science, Work function, Thin film, 0210 nano-technology
Abstract

Graphene/metal heterojunctions are ubiquitous in graphene-based devices and, therefore, have attracted increasing interest of researchers. Indeed, the literature on the field reports apparently contradictory results about the effect of a metal on graphene doping. Here, we elucidate the effect of metal nanostructuring and oxidation on the metal work function (WF) and, consequently, on the charge transfer and doping of graphene/metal hybrids. We show that nanostructuring and oxidation of metals provide a valid support to frame WF and doping variation in metal/graphene hybrids. Chemical vapour-deposited monolayer graphene has been transferred onto a variety of metal surfaces, including d-metals, such as Ag, Au, and Cu, and sp-metals, such as Al and Ga, configured as thin films or nanoparticle (NP) ensembles of various average sizes. The metal-induced charge transfer and the doping of graphene have been investigated using Kelvin probe force microscopy (KPFM), and corroborated by Raman spectroscopy and plasmonic ellipsometric spectroscopy. We show that when the appropriate WF of the metal is considered, without any assumption, taking into account WF variations by nanostructure and/or oxidation, a linear relationship between the metal WF and the doping of graphene is found. Specifically, for all metals, nanostructuring lowers the metal WF. In addition, using gold as an example, a critical metal nanoparticle size is found at which the direction of charge transfer, and consequently graphene doping, is inverted.

Published
2015

49. Gallium plasmonics: deep subwavelength spectroscopic imaging of single and interacting gallium nanoparticles

Author

Toon Coenen, Mark W. Knight, April S. Brown, Yang Yang, Maria Losurdo, Henry O. Everitt, Benjamin J. M. Brenny, and Albert Polman

Subjects
Materials science, business.industry, General Engineering, Physics::Optics, General Physics and Astronomy, chemistry.chemical_element, Nanoparticle, Cathodoluminescence, Substrate (electronics), medicine.disease_cause, Epitaxy, symbols.namesake, Optics, chemistry, medicine, symbols, Optoelectronics, General Materials Science, Gallium, business, Raman spectroscopy, Ultraviolet, Plasmon
Abstract

Gallium has recently been demonstrated as a phase-change plasmonic material offering UV tunability, facile synthesis, and a remarkable stability due to its thin, self-terminating native oxide. However, the dense irregular nanoparticle (NP) ensembles fabricated by molecular-beam epitaxy make optical measurements of individual particles challenging. Here we employ hyperspectral cathodoluminescence (CL) microscopy to characterize the response of single Ga NPs of various sizes within an irregular ensemble by spatially and spectrally resolving both in-plane and out-of-plane plasmonic modes. These modes, which include hybridized dipolar and higher-order terms due to phase retardation and substrate interactions, are correlated with finite difference time domain (FDTD) electrodynamics calculations that consider the Ga NP contact angle, substrate, and native Ga/Si surface oxidation. This study experimentally confirms previous theoretical predictions of plasmonic size-tunability in single Ga NPs and demonstrates that the plasmonic modes of interacting Ga nanoparticles can hybridize to produce strong hot spots in the ultraviolet. The controlled, robust UV plasmonic resonances of gallium nanoparticles are applicable to energy- and phase-specific applications such as optical memory, environmental remediation, and simultaneous fluorescence and surface-enhanced Raman spectroscopies.

Published
2015

50. List of Contributors

Author

Hiroshi Amano, Yamina André, Hajime Asahi, John E. Ayers, Michael J. Aziz, Bhavtosh Bansal, Arnab Bhattacharya, Robert M. Biefeld, A.A. Bol, April S. Brown, Robert Cadoret, Jeffrey G. Cederberg, Xiaogang Chen, Enrique D. Cobas, James J. Coleman, Armin Dadgar, Paul G. Evans, Roberto Fornari, Hiroshi Fujioka, D. Kurt Gaskill, Evelyne Gil, Mark S. Goorsky, Brett C. Johnson, W.M.M. Kessels, Jeong Dong Kim, Tsunenobu Kimoto, H.C.M. Knoops, G. Koblmüller, Daniel D. Koleske, Alois Krost, Thomas F. Kuech, J.R. Lang, Hongdong Li, Xiuling Li, Maria Losurdo, Fumihiro Matsukura, Michael G. Mauk, Jeffrey C. McCallum, Kathleen M. McCreary, Xin Miao, Osamu Nakatsuka, Nathan Newman, Tatau Nishinaga, Hideo Ohno, S.E. Potts, Aaron J. Ptak, Joan M. Redwing, Zachary R. Robinson, Scott W. Schmucker, Clemens Simbrunner, Helmut Sitter, Marek Skowronski, Josef W. Spalenka, J.S. Speck, Wolfgang Stolz, E. Suhir, Roman Talalaev, Hidekazu Tanaka, Agnès Trassoudaine, Mahmoud Vahidi, Kerstin Volz, E.C. Young, and Shigeaki Zaima

Published
2015

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