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

Autor:	L. Ren, L. Lombez, C. Robert, D. Beret, D. Lagarde, B. Urbaszek, P. Renucci, T. Taniguchi, K. Watanabe, S. A. Crooker, X. Marie
Rok vydání:	2022
Předmět:	Condensed Matter - Materials Science Condensed Matter - Mesoscale and Nanoscale Physics Mesoscale and Nanoscale Physics (cond-mat.mes-hall) Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences Physics::Optics General Physics and Astronomy
Zdroj:	Physical Review Letters. 129
ISSN:	1079-7114 0031-9007
DOI:	10.1103/physrevlett.129.027402
Popis:	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.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::fb59d932a74216ead75f7a3e44d2064d https://doi.org/10.1103/physrevlett.129.027402 Zobrazit plný text záznamu