Your browser doesn't support javascript.
loading
80% Valley Polarization of Free Carriers in Singly Oriented Single-Layer WS_{2} on Au(111).
Beyer, H; Rohde, G; Grubisic Cabo, A; Stange, A; Jacobsen, T; Bignardi, L; Lizzit, D; Lacovig, P; Sanders, C E; Lizzit, S; Rossnagel, K; Hofmann, P; Bauer, M.
Affiliation
  • Beyer H; Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany.
  • Rohde G; Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany.
  • Grubisic Cabo A; Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, 8000 Aarhus C, Denmark.
  • Stange A; Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany.
  • Jacobsen T; Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany.
  • Bignardi L; Department of Physics, University of Trieste, 34127 Trieste, Italy.
  • Lizzit D; Elettra-Sincrotrone Trieste S.C.p.A., 34149 Trieste, Italy.
  • Lacovig P; Elettra-Sincrotrone Trieste S.C.p.A., 34149 Trieste, Italy.
  • Sanders CE; Elettra-Sincrotrone Trieste S.C.p.A., 34149 Trieste, Italy.
  • Lizzit S; Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell OX11 0QX, United Kingdom.
  • Rossnagel K; Elettra-Sincrotrone Trieste S.C.p.A., 34149 Trieste, Italy.
  • Hofmann P; Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany.
  • Bauer M; Ruprecht-Haensel-Labor, Christian-Albrechts-Universität zu Kiel und Deutsches Elektronen-Synchrotron DESY, 24098 Kiel und 22607 Hamburg, Germany.
Phys Rev Lett ; 123(23): 236802, 2019 Dec 06.
Article in En | MEDLINE | ID: mdl-31868459
ABSTRACT
We employ time- and angle-resolved photoemission spectroscopy to study the spin- and valley-selective photoexcitation and dynamics of free carriers at the K[over ¯] and K[over ¯]^{'} points in singly oriented single-layer WS_{2}/Au(111). Our results reveal that in the valence band maximum an ultimate valley polarization of free holes of 84% can be achieved upon excitation with circularly polarized light at room temperature. Notably, we observe a significantly smaller valley polarization for the photoexcited free electrons in the conduction band minimum. Clear differences in the carrier dynamics between electrons and holes imply intervalley scattering processes into dark states being responsible for the efficient depolarization of the excited electron population.

Full text: 1 Database: MEDLINE Language: En Year: 2019 Type: Article

Full text: 1 Database: MEDLINE Language: En Year: 2019 Type: Article