Long-Lived Hole Spin/Valley Polarization Probed by Kerr Rotation in Monolayer WSe2

Xinlin Song; Saien Xie; Kibum Kang; Jiwoong Park; Vanessa Sih

doi:10.1021/acs.nanolett.6b01727

Long-Lived Hole Spin/Valley Polarization Probed by Kerr Rotation in Monolayer WSe2

Nano Lett. 2016 Aug 10;16(8):5010-4. doi: 10.1021/acs.nanolett.6b01727. Epub 2016 Jul 28.

Authors

Xinlin Song¹, Saien Xie, Kibum Kang, Jiwoong Park², Vanessa Sih³

Affiliations

¹ Applied Physics Program, University of Michigan , 450 Church Street, Ann Arbor, Michigan 48109, United States.
² Kavli Institute at Cornell for Nanoscale Science , 245 East Avenue, Ithaca, New York 14853, United States.
³ Department of Physics, University of Michigan , 450 Church Street, Ann Arbor, Michigan 48109, United States.

PMID: 27466727
DOI: 10.1021/acs.nanolett.6b01727

Abstract

Time-resolved Kerr rotation and photoluminescence measurements are performed on MOCVD-grown monolayer tungsten diselenide (WSe2). We observe a surprisingly long-lived Kerr rotation signal (∼80 ns) at 10 K, which is attributed to spin/valley polarization of the resident holes. This polarization is robust to transverse magnetic field (up to 0.3 T). Wavelength-dependent measurements reveal that only excitation near the free exciton energy generates this long-lived spin/valley polarization.

Keywords: Kerr rotation; Tungsten diselenide; exciton; photoluminescence; spin polarization.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.