Optically initialized robust valley-polarized holes in monolayer WSe2

Handle URI:
http://hdl.handle.net/10754/583865
Title:
Optically initialized robust valley-polarized holes in monolayer WSe2
Authors:
Hsu, Wei-Ting; Chen, Yen-Lun; Chen, Chiang-Hsiao; Liu, Pang-Shiuan; Hou, Tuo-Hung; Li, Lain-Jong ( 0000-0002-4059-7783 ) ; Chang, Wen-Hao ( 0000-0003-4880-6006 )
Abstract:
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.
KAUST Department:
Physical Sciences and Engineering (PSE) Division
Citation:
Optically initialized robust valley-polarized holes in monolayer WSe2 2015, 6:8963 Nature Communications
Publisher:
Nature Publishing Group
Journal:
Nature Communications
Issue Date:
25-Nov-2015
DOI:
10.1038/ncomms9963
Type:
Article
ISSN:
2041-1723
Additional Links:
http://www.nature.com/doifinder/10.1038/ncomms9963
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorHsu, Wei-Tingen
dc.contributor.authorChen, Yen-Lunen
dc.contributor.authorChen, Chiang-Hsiaoen
dc.contributor.authorLiu, Pang-Shiuanen
dc.contributor.authorHou, Tuo-Hungen
dc.contributor.authorLi, Lain-Jongen
dc.contributor.authorChang, Wen-Haoen
dc.date.accessioned2015-12-14T09:54:48Zen
dc.date.available2015-12-14T09:54:48Zen
dc.date.issued2015-11-25en
dc.identifier.citationOptically initialized robust valley-polarized holes in monolayer WSe2 2015, 6:8963 Nature Communicationsen
dc.identifier.issn2041-1723en
dc.identifier.doi10.1038/ncomms9963en
dc.identifier.urihttp://hdl.handle.net/10754/583865en
dc.description.abstractA 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.en
dc.language.isoenen
dc.publisherNature Publishing Groupen
dc.relation.urlhttp://www.nature.com/doifinder/10.1038/ncomms9963en
dc.rightsThis work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/en
dc.titleOptically initialized robust valley-polarized holes in monolayer WSe2en
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalNature Communicationsen
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionDepartment of Electrophysics, National Chiao Tung University, Hsinchu 30010, Taiwanen
dc.contributor.institutionInstitute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwanen
dc.contributor.institutionDepartment of Automatic Control Engineering, Feng Chia University, Taichung 40724, Taiwanen
dc.contributor.institutionDepartment of Electronics Engineering and Institute of Electronics, National Chiao Tung University, Hsinchu 30010, Taiwanen
dc.contributor.institutionTaiwan Consortium of Emergent Crystalline Materials (TCECM), Ministry of Science and Technology, Taipei 10622, Taiwanen
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
kaust.authorLi, Lain-Jongen
All Items in KAUST are protected by copyright, with all rights reserved, unless otherwise indicated.