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Article Dans Une Revue Physical Review Letters Année : 2022

Optical Detection of Long Electron Spin Transport Lengths in a Monolayer Semiconductor

Lei Ren
  • Fonction : Auteur
Cedric Robert
  • Fonction : Auteur
Dorian Beret
Delphine Lagarde
  • Fonction : Auteur
Bernhard Urbaszek
Pierre Renucci
  • Fonction : Auteur
Takashi Taniguchi
  • Fonction : Auteur
Kenji Watanabe
Scott A. Crooker
  • Fonction : Auteur
Xavier Marie
S. A. Crooker
  • Fonction : Auteur

Résumé

Using a spatially-resolved optical pump-probe experiment, we measure the lateral transport of spin/valley polarized electrons over very long distances (tens of micrometers) in a single WSe2 monolayer. By locally pumping the Fermi sea of 2D electrons to a high degree of spin/valley polarization (up to 75%) using circularly-polarized light, the lateral diffusion of the electron polarization can be mapped out via the photoluminescence induced by a spatially-separated and linearly-polarized probe laser. Up to 25% spin-valley polarization is observed at pump-probe separations up to 20 microns. Characteristic spin/valley diffusion lengths of 18 +/- 3 um are revealed at low temperatures. The dependence on temperature, pump helicity, pump intensity, and electron density highlight the key roles played by spin relaxation time and pumping efficiency on polarized electron transport in monolayer semiconductors possessing spin-valley locking.

Dates et versions

hal-03863638 , version 1 (21-11-2022)

Identifiants

Citer

Lei Ren, Laurent Lombez, Cedric Robert, Dorian Beret, Delphine Lagarde, et al.. Optical Detection of Long Electron Spin Transport Lengths in a Monolayer Semiconductor. Physical Review Letters, 2022, 129 (2), pp.027402. ⟨10.1103/PhysRevLett.129.027402⟩. ⟨hal-03863638⟩
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