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Your search keyword '"Schonhense, G."' showing total 38 results
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38 results on '"Schonhense, G."'

1. Chirality in the Kagome Metal CsV$_3$Sb$_5$

Author

Elmers, H. J., Tkach, O., Lytvynenko, Y., Yogi, P., Schmitt, M., Biswas, D., Liu, J., Chernov, S. V., Hoesch, M., Kutnyakhov, D., Wind, N., Wenthaus, L., Scholz, M., Rossnagel, K., Gloskovskii, A., Schlueter, C., Winkelmann, A., Haghighirad, A. -A., Lee, T. -L., Sing, M., Claessen, R., Tacon, M. Le, Demsar, J., Schonhense, G., and Fedchenko, O.

Subjects
Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Superconductivity
Abstract

Using x-ray photoelectron diffraction (XPD) and angle-resolved photoemission spectroscopy, we study photoemission intensity changes related to changes in the geometric and electronic structure in the kagome metal CsV$_3$Sb$_5$ upon transition to an unconventional charge density wave (CDW) state. The XPD patterns reveal the presence of a chiral atomic structure in the CDW phase. Furthermore, using circularly polarized x-rays, we have found a pronounced non-trivial circular dichroism in the angular distribution of the valence band photoemission in the CDW phase, indicating a chirality of the electronic structure. This observation is consistent with the proposed orbital loop current order. In view of a negligible spontaneous Kerr signal in recent magneto-optical studies, the results suggest an antiferromagnetic coupling of the orbital magnetic moments along the $c$-axis. While the inherent structural chirality may also induce circular dichroism, the observed asymmetry values seem to be too large in the case of the weak structural distortions caused by the CDW.

Published
2024

2. Spin Mapping of Surface and Bulk Rashba States in Ferroelectric a-GeTe(111) Films

Author

Elmers, H. J., Wallauer, R., Liebmann, M., Kellner, J., Morgenstern, M., Wang, R. N., Boschker, J. E., Calarco, R., Rader, O., Kutnyakhov, D., Chernov, S. V., Medjanik, K., Tusche, C., Ellguth, M., Volfova, H., Braun, J., Minar, J., Ebert, H., and Schonhense, G.

Subjects
Condensed Matter - Materials Science
Abstract

A comprehensive mapping of the spin polarization of the electronic bands in ferroelectric a-GeTe(111) films has been performed using a time-of-flight momentum microscope equipped with an imaging spin filter that enables a simultaneous measurement of more than 10.000 data points (voxels). A Rashba type splitting of both surface and bulk bands with opposite spin helicity of the inner and outer Rashba bands is found revealing a complex spin texture at the Fermi energy. The switchable inner electric field of GeTe implies new functionalities for spintronic devices.

Published
2015
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3. Spectroscopic and microscopic study of vanadium oxide nanotubes

Author

Gloskovskii, A., Nepijko, S.A., Schonhense, G., Therese, H.A., Reiber, A., Kandpal, H.C., Fecher, G.H., Felser, C., Tremel, W., and Klimenkov, M.

Subjects
Nanotubes -- Research, Absorption spectra -- Usage, Physics
Abstract

Surface sensitive x-ray absorption spectroscopy (XAS) is compared to bulk sensitive electron energy loss spectroscopy (EELS) studies of vanadium oxide nanotubes, which are synthesized via sol-gel route. The obtained spectra have helped in distinguishing single-wall from multiwall [V.sub.2][O.sub.5] nanotubes.

Published
2007

5. Time-of-flight photoelectron spectromicroscopy of single MoS2 nanotubes

Author

Gloskovskii, A., Tremel, W., Oelsner, A., Nepijko, S.A., Zink, N., Cinchetti, M., Therese, H.A., Schonhense, G., Felser, C., Fecher, G.H., and Kandpal, H.C.

Subjects
Molybdenum -- Spectra, Molybdenum -- Electric properties, Electron configuration -- Research, Sulfur compounds -- Spectra, Sulfur compounds -- Electric properties, Photoelectron spectroscopy -- Usage, Physics
Abstract

Photoemission spectra of single MoS2 nanotubes deposited on a Si surface are recorded in order to explain their electronic structure. MoS2 nanotubes are found to be semiconducting with a band gap of about 1 eV.

Published
2006

6. Investigating magnetization dynamics in permalloy microstructures using time-resolved x-ray photoemission electron microscope

Author

Kuksov, A., Schneider, C.M., Oelsner, A., Krasyuk, A., Neeb, D., Schonhense, G., De Nadai C., and Brookes, N.B.

Subjects
Magnetization -- Research, Electron microscopes -- Usage, Physics
Abstract

The time-resolves x-ray photoemission electron microscope is used for examining the magnetization dynamics in permalloy microstructures. A characteristic blurring is exhibited by the domain images due to an averaging over a large number of fast nonreproducible remagnetization processes.

Published
2004

7. Angular distributions of photoelectrons ejected from fixed-in-space molecules of C[sub 3v]...

Author

Kuznetsov, V.V., Cherepkov, N.A., Fecher, G.H., and Schonhense, G.

Subjects
PHOTOELECTRONS, BEAM splitters, WAVE functions, SPHERICAL harmonics
Abstract

Studies the angular distributions of photoelectrons from fixed-in-space molecules of C[sub 3v] symmetry group for the particular case when the light beam in incoming parallel to the C[sub 3] rotational axis of the molecule. Basis of the consideration on the expansion of photoelectron wave functions in symmetry-adapted spherical harmonics.

Published
1999
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9. New applications of the magnetic X-ray circular dichroism method for surface-magnetism

Author

Nepijko S. A., Klais M., Oelsner A., Schmidt O., Fecher G. H., Schonhense G., Muschiol U., Schneider C. M., and Zennaro

Subjects
Condensed Matter::Materials Science
Abstract

It is shown that magnetic X-ray circular dichroism (MXCD) can be exploited in photoemission electron microscopy not only to visualize the domain structure of ferromagnets, but also to perform quantitative measurements of the stray magnetic fields at the domain boundaries. In the general situation, two MXCD images obtained at different extractor voltages are required. In specific cases, however, it suffices to consider a single image, if it is deformed by the stray magnetic fields compared to a known object geometry. The object geometry means its real shape, scratches or other defects. It is also possible to deposit a paramagnetic film structured in the form of stripes or a grid as a reference on the ferromagnetic sample being investigated.

Published
2002

38. Peculiarities of imaging one- and two-dimensional structures in an emission electron microscope. 1. theory

Author

Nepijko SA, Sedov NN, Ziethen C, Schonhense G, Merkel M, and Escher M

Abstract

Local changes in work function cause deviations of the electrical microfield near a sample surface as a result of the uniform accelerating field distribution between the sample (cathode) and the extractor electrode (anode). This results in a change in the electron trajectories. As a consequence, the microscope image shows remarkable changes in position, size, intensity and lateral resolution of distinct details, which can be quantitatively described by the calculations presented here. Analysing these effects in the image gives an opportunity to determine the real lateral size of the observed structures and the distribution of local contact potentials.

Published
2000
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