Optically initialized robust valley-polarized holes in monolayer WSe2

Wei Ting Hsu, Yen Lun Chen, Chiang Hsiao Chen, Pang Shiuan Liu, Tuo-Hung Hou, Lain Jong Li, Wen-Hao Chang*


研究成果: Article同行評審

126 引文 斯高帕斯(Scopus)


A robust valley polarization is a key prerequisite for exploiting valley pseudospin to carry information in next-generation electronics and optoelectronics. Although monolayer transition metal dichalcogenides with inherent spin-valley coupling offer a unique platform to develop such valleytronic devices, the anticipated long-lived valley pseudospin has not been observed yet. Here we demonstrate that robust valley-polarized holes in monolayer WSe 2 can be initialized by optical pumping. Using time-resolved Kerr rotation spectroscopy, we observe a long-lived valley polarization for positive trion with a lifetime approaching 1 ns at low temperatures, which is much longer than the trion recombination lifetime (1/410-20 ps). The long-lived valley polarization arises from the transfer of valley pseudospin from photocarriers to resident holes in a specific valley. The optically initialized valley pseudospin of holes remains robust even at room temperature, which opens up the possibility to realize room-temperature valleytronics based on transition metal dichalcogenides.

頁(從 - 到)1-8
期刊Nature Communications
出版狀態Published - 25 11月 2015


深入研究「Optically initialized robust valley-polarized holes in monolayer WSe2」主題。共同形成了獨特的指紋。