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1. Microfluidic cell engineering on high-density microelectrode arrays for assessing structure-function relationships in living neuronal networks

Author

Sato, Yuya, Yamamoto, Hideaki, Kato, Hideyuki, Tanii, Takashi, Sato, Shigeo, and Hirano-Iwata, Ayumi

Subjects
Quantitative Biology - Neurons and Cognition
Abstract

Neuronal networks in dissociated culture combined with cell engineering technology offer a pivotal platform to constructively explore the relationship between structure and function in living neuronal networks. Here, we fabricated defined neuronal networks possessing a modular architecture on high-density microelectrode arrays (HD-MEAs), a state-of-the-art electrophysiological tool for recording neural activity with high spatial and temporal resolutions. We first established a surface coating protocol using a cell-permissive hydrogel to stably attach polydimethylsiloxane microfluidic film on the HD-MEA. We then recorded the spontaneous neural activity of the engineered neuronal network, which revealed an important portrait of the engineered neuronal network--modular architecture enhances functional complexity by reducing the excessive neural correlation between spatially segregated modules. The results of this study highlight the impact of HD-MEA recordings combined with cell engineering technologies as a novel tool in neuroscience to constructively assess the structure-function relationships in neuronal networks., Comment: 18 pages, 5 figures

Published
2022
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2. Position-controlled functionalization of vacancies in silicon by single-ion implanted germanium atoms

Author

Achilli, Simona, Le, Nguyen H., Fratesi, Guido, Manini, Nicola, Onida, Giovanni, Turchetti, Marco, Ferrari, Giorgio, Shinada, Takahiro, Tanii, Takashi, and Prati, Enrico

Subjects
Condensed Matter - Materials Science
Abstract

Special point defects in semiconductors have been envisioned as suitable components for quantum-information technology. The identification of new deep centers in silicon that can be easily activated and controlled is a main target of the research in the field. Vacancy-related complexes are suitable to provide deep electronic levels but they are hard to control spatially. With the spirit of investigating solid state devices with intentional vacancy-related defects at controlled position, here we report on the functionalization of silicon vacancies by implanting Ge atoms through single-ion implantation, producing Ge-vacancy (GeV) complexes. We investigate the quantum transport through an array of GeV complexes in a silicon-based transistor. By exploiting a model based on an extended Hubbard Hamiltonian derived from ab-initio results we find anomalous activation energy values of the thermally activated conductance of both quasi-localized and delocalized many-body states, compared to conventional dopants. We identify such states, forming the upper Hubbard band, as responsible of the experimental sub-threshold transport across the transistor. The combination of our model with the single-ion implantation method enables future research for the engineering of GeV complexes towards the creation of spatially controllable individual defects in silicon for applications in quantum information technologies.

Published
2021

3. GeVn complexes for silicon-based room-temperature single-atom nanoelectronics

Author

Achilli, Simona, Manini, Nicola, Onida, Giovanni, Shinada, Takahiro, Tanii, Takashi, and Prati, Enrico

Subjects
Physics - Computational Physics, Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We characterize germanium-vacancy GeVn complexes in silicon using first-principles Density Functional Theory calculations with screening-dependent hybrid functionals. We report on the local geometry and electronic excited states of these defects, including charge transition levels corresponding to the addition of one or more electrons to the defect. Our main theoretical result concerns the GeV complex, which we show to give rise to two excited states deep in the gap, at -0.51 and -0.35 eV from the conduction band, consistently with the available spectroscopic data. The adopted theoretical scheme, suitable to compute a reliable estimate of the wavefunction decay, leads us to predict that such states are associated to an electron localization over a length of about 0.45 nm. By combining the electronic properties of the bare silicon vacancy, carrying deep states in the band gap, with the spatial controllability arising from single Ge ion implantation techniques, the GeVn complex emerges as a suitable ingredient for silicon-based room-temperature single-atom devices.

Published
2018

4. Control of the Correlation of Spontaneous Neuron Activity in Biological and Noise-activated CMOS Artificial Neural Microcircuits

Author

Hasani, Ramin M., Ferrari, Giorgio, Yamamoto, Hideaki, Kono, Sho, Ishihara, Koji, Fujimori, Soya, Tanii, Takashi, and Prati, Enrico

Subjects
Computer Science - Neural and Evolutionary Computing, Quantitative Biology - Neurons and Cognition, Quantitative Biology - Quantitative Methods
Abstract

There are several indications that brain is organized not on a basis of individual unreliable neurons, but on a micro-circuital scale providing Lego blocks employed to create complex architectures. At such an intermediate scale, the firing activity in the microcircuits is governed by collective effects emerging by the background noise soliciting spontaneous firing, the degree of mutual connections between the neurons, and the topology of the connections. We compare spontaneous firing activity of small populations of neurons adhering to an engineered scaffold with simulations of biologically plausible CMOS artificial neuron populations whose spontaneous activity is ignited by tailored background noise. We provide a full set of flexible and low-power consuming silicon blocks including neurons, excitatory and inhibitory synapses, and both white and pink noise generators for spontaneous firing activation. We achieve a comparable degree of correlation of the firing activity of the biological neurons by controlling the kind and the number of connection among the silicon neurons. The correlation between groups of neurons, organized as a ring of four distinct populations connected by the equivalent of interneurons, is triggered more effectively by adding multiple synapses to the connections than increasing the number of independent point-to-point connections. The comparison between the biological and the artificial systems suggests that a considerable number of synapses is active also in biological populations adhering to engineered scaffolds.

Published
2017

5. Room-temperature 1.54 $\mu$m photoluminescence of Er:O$_x$ centers at extremely low concentration in silicon

Author

Celebrano, Michele, Ghirardini, Lavinia, Biagioni, Paolo, Finazzi, Marco, Shimizu, Yasuo, Tu, Yuan, Inoue, Koji, Nagai, Yasuyoshi, Shinada, Takahiro, Chiba, Yuki, Abdelghafar, Ayman, Yano, Maasa, Tanii, Takashi, and Prati, Enrico

Subjects
Condensed Matter - Materials Science
Abstract

The demand for single photon sources at $\lambda~=~1.54~\mu$m, which follows from the consistent development of quantum networks based on commercial optical fibers, makes Er:O$_x$ centers in Si still a viable resource thanks to the optical transition of $Er^{3+}~:~^4I_{13/2}~\rightarrow~^4I_{15/2}$. Yet, to date, the implementation of such system remains hindered by its extremely low emission rate. In this Letter, we explore the room-temperature photoluminescence (PL) at the telecomm wavelength of very low implantation doses of $Er:O_x$ in $Si$. The emitted photons, excited by a $\lambda~=~792~nm$ laser in both large areas and confined dots of diameter down to $5~\mu$m, are collected by an inverted confocal microscope. The lower-bound number of detectable emission centers within our diffraction-limited illumination spot is estimated to be down to about 10$^4$, corresponding to an emission rate per individual ion of about $4~\times~10^{3}$ photons/s., Comment: 13 pages, 4 figures

Published
2017
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7. Enhancing photon collection from single shallow nitrogen-vacancy centers in diamond nanopillars for quantum heterodyne measurements

Author

Chanuntranont, Akirabha, primary, Otani, Kazuki, additional, Saito, Daiki, additional, Ueda, Yuki, additional, Tsugawa, Masato, additional, Usui, Shuntaro, additional, Miyake, Yuto, additional, TERAJI, Tokuyuki, additional, Onoda, Shinobu, additional, Shinada, Takahiro, additional, KAWARADA, Hiroshi, additional, and Tanii, Takashi, additional

Published
2023
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8. Detecting nuclear spins in an organosilane monolayer using nitrogen-vacancy centers for analysis of precursor self-assembly on diamond surface

Author

Ueda, Yuki, primary, Miyake, Yuto, additional, Chanuntranont, Akirabha, additional, Otani, Kazuki, additional, Tsugawa, Masato, additional, Saito, Daiki, additional, Usui, Shuntaro, additional, Teraji, Tokuyuki, additional, Onoda, Shinobu, additional, Shinada, Takahiro, additional, Kawarada, Hiroshi, additional, and Tanii, Takashi, additional

Published
2023
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16. Highly aligned 2D NV ensemble fabrication from nitrogen-terminated (111) surface

Author

Tetsuya, Tatsuishi, Kyotaro, Kanehisa, Taisuke, Kageura, Sonoda, Takahiro, Hata Yuki, Kazuto, Kawakatsu, Tanii, Takashi, Shinobu, Onoda, Stacey, Alastair, Kono, Shozo, Kawarada, Hiroshi, and Yuki, Hata

Abstract

The nitrogen vacancy (NV) center in diamond is fascinating and has a long spin coherence time. It is applied to magnetic sensors with high sensitivity (∼fT). To achieve a high sensitivity, an aligned NV ensemble is required. This paper presents a new methodology for the fabrication of two-dimensional (2D) aligned NV ensembles by using nitrogen-terminated (111) surface. To realize this, pure diamond growth and high nitrogen coverage on (111) surface were performed. As a result, we have succeeded in producing 2D NV ensembles, with 1 × 109 cm−2. Coherence time T2 was 2.45 μs. Also, Using dynamical decoupling, the decoherence sources were revealed. The alignment ratio along [111] axis was archived 60%. Thermal annealing of the nitrogen termination was introduced to improve the alignment ratio. After that, the alignment rate was up to 73%. This report shows that the aligned 2D NV ensemble has possibility to be applied for multiple quantum devices.

Published
2021

17. Spin Characterization of High-Density NV Ensemble Using Vacancies Created by Transmission Electron Microscope

Author

Hayasaka, Kyosuke, primary, Kanehisa, Kyotaro, additional, Tatsuishi, Tetsuya, additional, Saito, Yuta, additional, Ueda, Yuki, additional, Otani, Kazuki, additional, Tanii, Takashi, additional, Onoda, Shinobu, additional, Isoya, Junichi, additional, Enomoto, Shinpei, additional, Kono, Shozo, additional, and Kawarada, Hiroshi, additional

Published
2021
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20. Nitrogen-Terminated Diamond Surface for Nanoscale NMR by Shallow Nitrogen-Vacancy Centers

Author

Kawai, Sora, Yamano, Hayate, Sonoda, Takahiro, Kato, Kanami, J. Buendia, Jorge, Kageura, Taisuke, Fukuda, Ryosuke, Okada, Takuma, Tanii, Takashi, Higuchi, Taisei, Haruyama, Moriyoshi, Yamada, Keisuke, Onoda, Shinobu, Ohshima, Takeshi, Kada, Wataru, Hanaizumi, Osamu, Stacey, Alastair, Teraji, Tokuyuki, Kono, Shozo, Isoya, Junichi, and Kawarada, Hiroshi

Abstract

The nitrogen-vacancy (NV) center in diamond is the most promising candidate for quantum sensing because of its beneficial properties. For quantum-sensing applications, a shallow NV center is critical for approximating the sensing target on a diamond surface. Such shallow NV centers are strongly affected by the diamond surface termination. The properties of shallow NV centers in hydrogen-, oxygen-, and fluorine-terminated diamond have been well studied. In recent years, silicon-terminated diamond has also been investigated; however, the effect of silicon-terminated diamond on the properties of shallow NV centers remains unclear. Recently, the suitability of nitrogen-terminated diamond for shallow NV centers has been theoretically and experimentally examined; however, quantum sensing has not yet been performed. In this work, we evaluated the effect of silicon and nitrogen termination on shallow NV centers. The negatively charged state of shallow NV centers was unstable below silicon termination. In contrast, the properties of shallow NV centers in nitrogen-terminated diamond were satisfactory for quantum sensing and enabled 1H NMR detection. Our results are in good agreement with previous reports on silicon and nitrogen terminations and provide the perspective that the stability of shallow NV centers highly depends on the polarity of electron affinity of the diamond surface.

Published
2019

22. Single‐Ion Implantation: Position‐Controlled Functionalization of Vacancies in Silicon by Single‐Ion Implanted Germanium Atoms (Adv. Funct. Mater. 21/2021)

Author

Achilli, Simona, primary, Le, Nguyen H., additional, Fratesi, Guido, additional, Manini, Nicola, additional, Onida, Giovanni, additional, Turchetti, Marco, additional, Ferrari, Giorgio, additional, Shinada, Takahiro, additional, Tanii, Takashi, additional, and Prati, Enrico, additional

Published
2021
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24. Real-time imaging of single-molecule fluorescence with a zero-mode waveguide for the analysis of protein-protein interaction

Author

Miyake, Takeo, Tanii, Takashi, Sonobe, Hironori, Akahori, Rena, Shimamoto, Naonobu, Ueno, Taro, Funatsu, Takashi, and Ohdomari, Iwao

Subjects
Fluorescence -- Research, Waveguides -- Properties, Imaging systems -- Methods, Protein-protein interactions -- Research, Chemistry
Abstract

Real-time imaging of single-molecule fluorescence with a zero-mode waveguide (ZMW) was achieved. With modification of the ZMW geometry, the signal-to-background ratio is twice that obtainable with a conventional ZMW. The improved signal-to-background ratio makes it possible to visualize individual binding--release events between chaperonin GroEL and cochaperonin GroES at a concentration of 5 [micro]M. Two rate constants representing two-timer kinetics in the release of GroES from GroEL were measured with the ZMW, and the measurements agreed well with those made with a total internal reflection fluorescence microscopy. These results indicate that the novel ZMW makes feasible the direct observation of protein--protein interaction at an intracellular concentration in real time.

Published
2008

25. Alignment and Coherence Time of 2D Shallow NV Ensemble Fabricated from (111) Diamond

Author

Kanehisa, Kyotaro, Tatsuishi, Tetsuya, Sonoda, Takahiro, Kawakatsu, Kazuto, Hata, Yuki, Tanii, Takashi, Onoda, Shinobu, Stacey, Alastair, Moshkani, Mojtaba, Mildren, Rich, Isoya, Junichi, Kono, Shozo, and Kawarada, Hiroshi

Abstract

We established the method to fabricate two-dimensional (2D) shallow NV ensemble. We realized nitrogen-terminated (111) diamond surface with nitrogen radical exposure and grew very thin (approximately 10 nm) diamond film on the surface by microwave plasma-enhanced chemical vapor deposition (MPCVD). We counted the number of NV ensembles aligned in [111] direction of the NV ensembles which we observed. The probability of NV ensemble being aligned in [111] was 42 %. On the other hand, we changed the surface condition of N-terminated (111) diamond by thermal annealing. Then, we grew 10 nm diamond film on the surface. As a result, the probability of NV ensemble being aligned in [111] rose to 60 %. Also, s-factor developed from 0.44 to 0.52., 2020 International Conference on Solid State Devices and Materials

Published
2020

26. Aligned Two-Dimensional NV Ensemble Fabrication from (111) Nitrogen-Terminated Surface Embedded by High Purity Diamond

Author

Tatsuishi, Tetsuya, Sonoda, Takahiro, J. Buendia, Jorge, Kageura, Taisuke, Ishii, Yu, Nagaoka, Kiro, Hata, Yuki, Kawakatsu, Kazuto, Tanii, Takashi, Haruyama, Moriyoshi, Onoda, Shinobu, Stacey, Alastair, Teraji, Tokuyuki, Isoya, Junichi, Kono, Shozo, and Kawarada, Hiroshi

Abstract

Nitrogen vacancy (NV) center in diamond is expected as a magnetic sensor with high sensitivity at room temperature and single NV center succeeded in detecting 1H spins out of the substrate. For improvement magnetic sensitivity, both shallow and aligned NV ensemble is required since the magnetic sensitivity is inversely proportional to the root of number of NV centers contributing to the measurement. Delta-doping of N was tried by diamond growth on N-terminated (001) diamond and estimated 2D concentration of NV centers was 1 x 1011 cm-2. This method can control the depth of NV ensemble precisely unlike ion implantation or N-doped layer which are popular methods to fabricate NV ensemble. However, NV centers in (001) delta doped layer would be not aligned because possibility of each four sites adjacent to N becoming a vacancy are equivalent. In the case of (111) delta doping layer, NV centers will be aligned because a top site is more preferable to become a vacancy than other three equivalent sites. Recently, we established the method to fabricate N-terminated diamond with high coverage causing no damage on the surface [5, 6]. We partially succeeded to make aligned two-dimensional NV ensemble from N-terminated (111) diamond with half mono layer coverage embedded by high purity (111) diamond film., 2019 Materials Research Society Fall Meeting & Exhibit

Published
2019

35. New Delta Doping of Nitrogen for 2 Dimensionally Condensed NV C enter s Using Nitrogen Terminated Diamond Followed by High Purity Diamond Growth

Author

Tatsuishi, Tetsuya, Sonoda, Takahiro, J. Buendia, Jorge, Kageura, Taisuke, Kawakatsu, Kazuto, Hata, Yuki, Nagaoka, Kiro, Ishii, Yu, Tanii, Takashi, Haruyama, Moriyoshi, Yamada, Keisuke, Onoda, Shinobu, Kada, Wataru, Hanaizumi, Osamu, Stacey, Alastair, Teraji, Tokuyuki, Isoya, Junichi, Kono, Shozo, and Kawarada, Hiroshi

Abstract

We have successfully made 2 dimensionally condensed NV centers from N-terminated (111) diamond with near monolayer coverage. The N on the surface has been em-bedded by high purity homoepitaxial (111) diamond film to form NV centers. The NV centers made by these tech-niques were highly aligned. This new method of fabricat-ing NV centers is useful for application of NV centers to more sensitive quantum sensors., 2019 International Conference on Solid State Devices and Materials

Published
2019

42. Impact of modular organization on dynamical richness in cortical networks

Author

Yamamoto, Hideaki, primary, Moriya, Satoshi, additional, Ide, Katsuya, additional, Hayakawa, Takeshi, additional, Akima, Hisanao, additional, Sato, Shigeo, additional, Kubota, Shigeru, additional, Tanii, Takashi, additional, Niwano, Michio, additional, Teller, Sara, additional, Soriano, Jordi, additional, and Hirano-Iwata, Ayumi, additional

Published
2018
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43. Lithographically engineered shallow nitrogen-vacancy centers in diamond for external nuclear spin sensing

Author

Fukuda, Ryosuke, primary, Balasubramanian, Priyadharshini, additional, Higashimata, Itaru, additional, Koike, Godai, additional, Okada, Takuma, additional, Kagami, Risa, additional, Teraji, Tokuyuki, additional, Onoda, Shinobu, additional, Haruyama, Moriyoshi, additional, Yamada, Keisuke, additional, Inaba, Masafumi, additional, Yamano, Hayate, additional, Stürner, Felix M, additional, Schmitt, Simon, additional, McGuinness, Liam P, additional, Jelezko, Fedor, additional, Ohshima, Takeshi, additional, Shinada, Takahiro, additional, Kawarada, Hiroshi, additional, Kada, Wataru, additional, Hanaizumi, Osamu, additional, Tanii, Takashi, additional, and Isoya, Junichi, additional

Published
2018
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45. Photopatterning Proteins and Cells in Aqueous Environment Using TiO2 Photocatalysis

Author

Yamamoto, Hideaki, Demura, Takanori, Sekine, Kohei, Kono, Sho, Niwano, Michio, Hirano-Iwata, Ayumi, and Tanii, Takashi

Subjects
Neurons, Titanium, Extracellular Matrix Proteins, Tissue Scaffolds, Surface Properties, Ultraviolet Rays, Water, Bioengineering, Biocompatible Materials, Silanes, Photochemical Processes, PC12 Cells, Catalysis, Rats, Cell Adhesion, Animals, Glass
Abstract

Organic contaminants adsorbed on the surface of titanium dioxide (TiO2) can be decomposed by photocatalysis under ultraviolet (UV) light. Here we describe a novel protocol employing the TiO2 photocatalysis to locally alter cell affinity of the substrate surface. For this experiment, a thin TiO2 film was sputter-coated on a glass coverslip, and the TiO2 surface was subsequently modified with an organosilane monolayer derived from octadecyltrichlorosilane (OTS), which inhibits cell adhesion. The sample was immersed in a cell culture medium, and focused UV light was irradiated to an octagonal region. When a neuronal cell line PC12 cells were plated on the sample, cells adhered only on the UV-irradiated area. We further show that this surface modification can also be performed in situ, i.e., even when cells are growing on the substrate. Proper modification of the surface required an extracellular matrix protein collagen to be present in the medium at the time of UV irradiation. The technique presented here can potentially be employed in patterning multiple cell types for constructing coculture systems or to arbitrarily manipulate cells under culture.

Published
2015

46. 154 μm photoluminescence from Er:O_x centers at extremely low concentration in silicon at 300 K

Author

Celebrano, Michele, primary, Ghirardini, Lavinia, additional, Finazzi, Marco, additional, Shimizu, Yasuo, additional, Tu, Yuan, additional, Inoue, Koji, additional, Nagai, Yasuyoshi, additional, Shinada, Takahiro, additional, Chiba, Yuki, additional, Abdelghafar, Ayman, additional, Yano, Maasa, additional, Tanii, Takashi, additional, and Prati, Enrico, additional

Published
2017
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47. Atom probe study of erbium and oxygen co-implanted silicon

Author

Shimizu, Yasuo, primary, Tu, Yuan, additional, Abdelghafar, Ayman, additional, Yano, Maasa, additional, Suzuki, Yudai, additional, Tanii, Takashi, additional, Shinada, Takahiro, additional, Prati, Enrico, additional, Celebrano, Michele, additional, Finazzi, Marco, additional, Ghirardini, Lavinia, additional, Inoue, Koji, additional, and Nagai, Yasuyoshi, additional

Published
2017
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48. Revisiting room-temperature 1.54 μιη photoluminescence of ErOx centers in silicon at extremely low concentration

Author

Prati, Enrico, primary, Celebrano, Michele, additional, Ghirardini, Lavinia, additional, Biagioni, Paolo, additional, Finazzi, Marco, additional, Shimizu, Yasuo, additional, Tu, Yuan, additional, Inoue, Koji, additional, Nagai, Yasuyoshi, additional, Shinada, Takahiro, additional, Chiba, Yuki, additional, Abdelghafar, Ayman, additional, Yano, Maasa, additional, and Tanii, Takashi, additional

Published
2017
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49. Effect of a radical exposure nitridation surface on the charge stability of shallow nitrogen-vacancy centers in diamond

Author

Kageura, Taisuke, primary, Kato, Kanami, additional, Yamano, Hayate, additional, Suaebah, Evi, additional, Kajiya, Miki, additional, Kawai, Sora, additional, Inaba, Masafumi, additional, Tanii, Takashi, additional, Haruyama, Moriyoshi, additional, Yamada, Keisuke, additional, Onoda, Shinobu, additional, Kada, Wataru, additional, Hanaizumi, Osamu, additional, Teraji, Tokuyuki, additional, Isoya, Junichi, additional, Kono, Shozo, additional, and Kawarada, Hiroshi, additional

Published
2017
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50. Charge state stabilization of shallow nitrogen vacancy centers in diamond by oxygen surface modification

Author

Yamano, Hayate, primary, Kawai, Sora, additional, Kato, Kanami, additional, Kageura, Taisuke, additional, Inaba, Masafumi, additional, Okada, Takuma, additional, Higashimata, Itaru, additional, Haruyama, Moriyoshi, additional, Tanii, Takashi, additional, Yamada, Keisuke, additional, Onoda, Shinobu, additional, Kada, Wataru, additional, Hanaizumi, Osamu, additional, Teraji, Tokuyuki, additional, Isoya, Junichi, additional, and Kawarada, Hiroshi, additional

Published
2017
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