Studying local Berry curvature in 2H-WSe2 by circular dichroism photoemission utilizing crystal mirror plane
| Autor: | Seung Ryong Park, Soohyun Cho, Changyoung Kim, Jisook Hong, Soonsang Huh, J. D. Denlinger, Byeong-Gyu Park, Jin-Hong Park, Ji Hoon Shim, Wonshik Kyung |
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| Rok vydání: | 2021 |
| Předmět: |
Physics
Angular momentum Multidisciplinary Condensed matter physics Antisymmetric relation Science Position and momentum space 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Crystal Brillouin zone Atomic orbital 0103 physical sciences Perpendicular Medicine Berry connection and curvature 010306 general physics 0210 nano-technology |
| Zdroj: | Scientific reports, vol 11, iss 1 Scientific Reports, Vol 11, Iss 1, Pp 1-9 (2021) |
| Popis: | It was recently reported that circular dichroism in angle-resolved photoemission spectroscopy (CD-ARPES) can be used to observe the Berry curvature in 2H-WSe2 (Cho et al. in Phys Rev Lett 121:186401, 2018). In that study, the mirror plane of the experiment was intentionally set to be perpendicular to the crystal mirror plane, such that the Berry curvature becomes a symmetric function about the experimental mirror plane. In the present study, we performed CD-ARPES on 2H-WSe2 with the crystal mirror plane taken as the experimental mirror plane. Within such an experimental constraint, two experimental geometries are possible for CD-ARPES. The Berry curvature distributions for the two geometries are expected to be antisymmetric about the experimental mirror plane and exactly opposite to each other. Our experimental CD intensities taken with the two geometries were found to be almost opposite near the corners of the 2D projected hexagonal Brillouin zone (BZ) and were almost identical near the center of the BZ. This observation is well explained by taking the Berry curvature or the atomic orbital angular momentum (OAM) into account. The Berry curvature (or OAM) contribution to the CD intensities can be successfully extracted through a comparison of the CD-ARPES data for the two experimental geometries. Thus, the CD-ARPES experimental procedure described provides a method for mapping Berry curvature in the momentum space of topological materials, such as Weyl semimetals. |
| Databáze: | OpenAIRE |
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