dc.contributor.author | Huang, Jiani | |
dc.contributor.author | Hoang, Thang B. | |
dc.contributor.author | Ming, Tian | |
dc.contributor.author | Kong, Jing | |
dc.contributor.author | Mikkelsen, Maiken H. | |
dc.date.accessioned | 2017-05-18T20:58:14Z | |
dc.date.available | 2017-05-18T20:58:14Z | |
dc.date.issued | 2017-02 | |
dc.date.submitted | 2017-01 | |
dc.identifier.issn | 2469-9950 | |
dc.identifier.issn | 2469-9969 | |
dc.identifier.uri | http://hdl.handle.net/1721.1/109187 | |
dc.description.abstract | Monolayer transition metal dichalcogenides (TMDCs) offer a tantalizing platform for control of both spin and valley degrees of freedom, which may enable future optoelectronic devices with enhanced and novel functionalities. Here, we investigate the valley dynamics of two prototypical members of TMDCs, namely MoS₂ and WS e₂, using time-resolved Kerr rotation (TRKR) at temperatures from 10 K to 300 K. This pump-probe technique enables sub-picosecond temporal resolution, providing insight into ultrafast valley dynamics, which is inaccessible by polarized and time-resolved photoluminescence spectroscopy. Bi-exponential decay dynamics were observed for both materials at low temperatures, and the fast decay component indicated a rapid exciton valley depolarization time (<10ps) due to strong Coulomb exchange interactions between the K valleys. However, the slow decay components (several tens of picoseconds) were attributed to different origins in the two materials, which were further elucidated by temperature-dependent TRKR measurements. Moreover, the spatial dependence of the TRKR intensity across MoS₂ monolayer flakes indicated a weaker valley polarization near the edges, which is likely associated with quenched excitons near the grain boundaries or a disordered edge region in chemical vapor deposition–grown monolayers. These temporal and spatial TRKR measurements reveal insight into the complex dynamics of valley excitonic states, which will be critical for valleytronic applications of monolayer TMDCs. | en_US |
dc.description.sponsorship | United States. Department of Energy (DESC0001088) | en_US |
dc.publisher | American Physical Society | en_US |
dc.relation.isversionof | http://dx.doi.org/10.1103/PhysRevB.95.075428 | en_US |
dc.rights | Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. | en_US |
dc.source | American Physical Society | en_US |
dc.title | Temporal and spatial valley dynamics in two-dimensional semiconductors probed via Kerr rotation | en_US |
dc.type | Article | en_US |
dc.identifier.citation | Huang, Jiani; Hoang, Thang B.; Ming, Tian; Kong, Jing and Mikkelsen, Maiken H. "Temporal and spatial valley dynamics in two-dimensional semiconductors probed via Kerr rotation." Physical Review B 95, no. 075428 (February 2017): 1-7 ©2017 American Physical Society | en_US |
dc.contributor.department | Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science | en_US |
dc.contributor.department | Massachusetts Institute of Technology. Department of Mechanical Engineering | en_US |
dc.contributor.department | Massachusetts Institute of Technology. Research Laboratory of Electronics | en_US |
dc.contributor.mitauthor | Ming, Tian | |
dc.contributor.mitauthor | Kong, Jing | |
dc.relation.journal | Physical Review B | en_US |
dc.eprint.version | Final published version | en_US |
dc.type.uri | http://purl.org/eprint/type/JournalArticle | en_US |
eprint.status | http://purl.org/eprint/status/PeerReviewed | en_US |
dc.date.updated | 2017-02-24T23:00:04Z | |
dc.language.rfc3066 | en | |
dc.rights.holder | American Physical Society | |
dspace.orderedauthors | Huang, Jiani; Hoang, Thang B.; Ming, Tian; Kong, Jing; Mikkelsen, Maiken H. | en_US |
dspace.embargo.terms | N | en_US |
dc.identifier.orcid | https://orcid.org/0000-0002-6971-8817 | |
dc.identifier.orcid | https://orcid.org/0000-0003-0551-1208 | |
mit.license | PUBLISHER_POLICY | en_US |