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

Song, Xinlin; Xie, Saien; Kang, Kibum; Park, Jiwoong; Sih, Vanessa · Nano Lett · 2016

basic_science · Level V

Where this comes from

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.