skip to main content

Title: 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.
Authors:
ORCiD logo ; ; ; ; ; ; ; ORCiD logo ; ORCiD logo
Publication Date:
OSTI Identifier:
1114280
DOE Contract Number:
AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Nature Physics; Journal Volume: 10; Journal Issue: 2
Publisher:
Nature Publishing Group (NPG)
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE