Imaging Spin Dynamics in Monolayer WS2 by Time-Resolved Kerr Rotation Microscopy
Abstract
Monolayer transition metal dichalcogenides (TMD) have immense potential for future spintronic and valleytronic applications due to their 2D nature and long spin/valley lifetimes. We investigate the origin of these long-lived states in n-type WS2 using time-resolved Kerr rotation microscopy and photoluminescence microscopy with similar to 1 mu m spatial resolution. Comparing the spatial dependence of the Kerr rotation signal and the photoluminescence reveals a correlation with neutral exciton emission, which is likely due to the transfer of angular momentum to resident conduction electrons with long spin/valley lifetimes. In addition, we observe an unexpected anticorrelation between the Kerr rotation and trion emission, which provides evidence for the presence of long-lived spin/valley-polarized dark trions. We also find that the spin/valley polarization in WS2 is robust to magnetic fields up to 700 mT, indicative of spins and valleys that are stabilized with strong spin-orbit fields.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 30, 2017
- Accession Number
- AD1102119
Entities
People
- Berend T Jonker
- Edward Jr J. Cichewicz
- Elizabeth J. Mccormick
- Iwan B. Martin
- Kathleen M McCreary
- Michael J. Newburger
- Roland K Kawakami
- Simranjeet Singh
- Yunqiu K. Luo
Organizations
- United States Naval Research Laboratory