Optically initialized robust valley-polarized holes in monolayer WSe2
Type
ArticleAuthors
Hsu, Wei-TingChen, Yen-Lun
Chen, Chiang-Hsiao
Liu, Pang-Shiuan
Hou, Tuo-Hung
Li, Lain-Jong

Chang, Wen-Hao

KAUST Department
Material Science and Engineering ProgramPhysical Science and Engineering (PSE) Division
Date
2015-11-25Online Publication Date
2015-11-25Print Publication Date
2015-12Permanent link to this record
http://hdl.handle.net/10754/583865
Metadata
Show full item recordAbstract
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 WSe2 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 (~10–20 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.Citation
Optically initialized robust valley-polarized holes in monolayer WSe2 2015, 6:8963 Nature CommunicationsPublisher
Springer NatureJournal
Nature CommunicationsPubMed ID
26603335Additional Links
http://www.nature.com/doifinder/10.1038/ncomms9963ae974a485f413a2113503eed53cd6c53
10.1038/ncomms9963
Scopus Count
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