Imaging Spin Dynamics in Monolayer WS2 by Time-Resolved Kerr Rotation Microscopy

Autor:	Bushong, Elizabeth J., Newburger, Michael, Yunqiu, Luo, McCreary, Kathleen M., Singh, Simranjeet, Martin, Iwan B., Cichewicz Jr., Edward J., Jonker, Berend T., Kawakami, Roland K.
Rok vydání:	2016
Předmět:	Condensed Matter - Mesoscale and Nanoscale Physics
Zdroj:	McCormick et al 2017 2D Mater. https://doi.org/10.1088/2053-1583/aa98ae
Druh dokumentu:	Working Paper
DOI:	10.1088/2053-1583/aa98ae
Popis:	Monolayer transition metal dichalcogenides (TMD) have immense potential for future spintronic and valleytronic applications due to their two-dimensional 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 ~1 micron 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. Comment: 27 pages, 10 figures
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/1602.03568 Zobrazit plný text záznamu View this record from Arxiv