Web of Science: 8 citas, Scopus: 7 citas, Google Scholar: citas,
Spin states protected from intrinsic electron-phonon coupling reaching 100 ns lifetime at room temperature in MoSe₂
Ersfeld, Manfred (RWTH Aachen University)
Volmer, Frank (RWTH Aachen University)
Melo, Pedro Miguel M.C. de (Université de Liège. Complex and Entangled Systems from Atoms to Materials)
Winter, Robin de (RWTH Aachen University)
Heithoff, Maximilian (RWTH Aachen University)
Zanolli, Zeila (Institut Català de Nanociència i Nanotecnologia)
Stampfer, Cristoph (RWTH Aachen University)
Verstraete, Matthieu J. (Université de Liège. Complex and Entangled Systems from Atoms to Materials)
Beschoten, Bernd (RWTH Aachen University)

Fecha: 2019
Resumen: We present time-resolved Kerr rotation measurements, showing spin lifetimes of over 100 ns at room temperature in monolayer MoSe. These long lifetimes are accompanied by an intriguing temperature-dependence of the Kerr amplitude, which increases with temperature up to 50 K and then abruptly switches sign. Using ab initio simulations, we explain the latter behavior in terms of the intrinsic electron-phonon coupling and the activation of transitions to secondary valleys. The phonon-assisted scattering of the photoexcited electron-hole pairs prepares a valley spin polarization within the first few ps after laser excitation. The sign of the total valley magnetization, and thus the Kerr amplitude, switches as a function of temperature, as conduction and valence band states exhibit different phonon-mediated intervalley scattering rates. However, the electron-phonon scattering on the ps time scale does not provide an explanation for the long spin lifetimes. Hence, we deduce that the initial spin polarization must be transferred into spin states, which are protected from the intrinsic electron-phonon coupling, and are most likely resident charge carriers, which are not part of the itinerant valence or conduction band states.
Nota: Número d'acord de subvenció EC/H2020/824143
Nota: Número d'acord de subvenció EC/H2020/785219
Nota: Número d'acord de subvenció EC/H2020/653838
Nota: Número d'acord de subvenció MINECO/SEV-2017-0706
Nota: Número d'acord de subvenció MINECO/RYC-2016-19344
Nota: Número d'acord de subvenció AGAUR/2017/SGR-1506
Derechos: Tots els drets reservats.
Lengua: Anglès
Documento: article ; recerca ; submittedVersion
Materia: Transition metal dichalcogenides ; Monolayer MoSe₂ ; Time-resolved Kerr rotation ; Spin lifetime ; Electron−phonon coupling
Publicado en: Nano letters, Vol. 19, issue 6 (June 2019) , p. 4083-4090, ISSN 1530-6992

DOI: 10.1021/acs.nanolett.9b01485


Preprint
10 p, 2.0 MB

El registro aparece en las colecciones:
Documentos de investigación > Documentos de los grupos de investigación de la UAB > Centros y grupos de investigación (producción científica) > Ciencias > Institut Català de Nanociència i Nanotecnologia (ICN2)
Artículos > Artículos de investigación
Artículos > Artículos publicados

 Registro creado el 2019-11-19, última modificación el 2020-11-07



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