Spin–layer locking effects in optical orientation of exciton spin in bilayer WSe2
Coupling degrees of freedom of distinct nature plays a critical role in numerous physical phenomena1, 2, 3, 4, 5, 6, 7, 8, 9, 10. The recent emergence of layered materials11, 12, 13 provides a laboratory for studying the interplay between internal quantum degrees of freedom of electrons14, 15. Here we report new coupling phenomena connecting real spin with layer pseudospins in bilayer WSe2. In polarization-resolved photoluminescence measurements, we observe large spin orientation of neutral and charged excitons by both circularly and linearly polarized excitation, with the trion spectrum splitting into a doublet at large vertical electrical field. These observations can be explained as a locking of spin and layer pseudospin in a given valley15, where the doublet implies an electrically induced spin splitting. The observed distinctive behaviour of the trion doublet under polarized excitation further provides spectroscopic evidence of interlayer and intralayer trion species, a promising step towards optical manipulation in van der Waals heterostructures16 through interlayer excitons.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1114280
- Journal Information:
- Nature Physics, Vol. 10, Issue 2; ISSN 1745-2473
- Publisher:
- Nature Publishing Group (NPG)
- Country of Publication:
- United States
- Language:
- English
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