Phonon Dephasing Dynamics in MoS2.
Nano Lett
; 21(3): 1434-1439, 2021 Feb 10.
Article
em En
| MEDLINE
| ID: mdl-33508204
A variety of quantum degrees of freedom, e.g., spins, valleys, and localized emitters, in atomically thin van der Waals materials have been proposed for quantum information applications, and they inevitably couple to phonons. Here, we directly measure the intrinsic optical phonon decoherence in monolayer and bulk MoS2 by observing the temporal evolution of the spectral interference of Stokes photons generated by pairs of laser pulses. We find that a prominent optical phonon mode E2g exhibits a room-temperature dephasing time of â¼7 ps in both the monolayer and bulk. This dephasing time extends to â¼20 ps in the bulk crystal at â¼15 K, which is longer than previously thought possible. First-principles calculations suggest that optical phonons decay via two types of three-phonon processes, in which a pair of acoustic phonons with opposite momentum are generated.
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01-internacional
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MEDLINE
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article