relation: https://epub.uni-regensburg.de/56317/
title: Nonclassical Exciton Diffusion in Monolayer WSe2
creator: Wagner, Koloman
creator: Zipfel, Jonas
creator: Rosati, Roberto
creator: Wietek, Edith
creator: Ziegler, Jonas D.
creator: Brem, Samuel
creator: Perea-Causín, Raül
creator: Taniguchi, Takashi
creator: Watanabe, Kenji
creator: Glazov, Mikhail M.
creator: Malic, Ermin
creator: Chernikov, Alexey
subject: 530 Physik
subject: ddc:530
description: We experimentally demonstrate time-resolved exciton propagation in a monolayer semiconductor at cryogenic temperatures. Monitoring phonon-assisted recombination of dark states, we find a highly unusual case of exciton diffusion. While at 5 K the diffusivity is intrinsically limited by acoustic phonon scattering, we observe a pronounced decrease of the diffusion coefficient with increasing temperature, far below the activation threshold of higher-energy phonon modes. This behavior corresponds neither to well-known regimes of semiclassical free-particle transport nor to the thermally activated hopping in systems with strong localization. Its origin is discussed in the framework of both microscopic numerical and semiphenomenological analytical models illustrating the observed characteristics of nonclassical propagation. Challenging the established description of mobile excitons in monolayer semiconductors, these results open up avenues to study quantum transport phenomena for excitonic quasiparticles in atomically thin van der Waals materials and their heterostructures.
publisher: AMER PHYSICAL SOC
date: 2021
type: info:eu-repo/semantics/article
type: Artikel
type: doc-type:article
type: NonPeerReviewed
identifier:   Wagner, Koloman  <http://orcid.org/0000-0001-5561-5318>, Zipfel, Jonas  <http://orcid.org/0000-0002-3149-9567>, Rosati, Roberto  <http://orcid.org/0000-0002-2514-3425>, Wietek, Edith  <http://orcid.org/0000-0001-6681-9260>, Ziegler, Jonas D.  <http://orcid.org/0000-0002-2683-5124>, Brem, Samuel  <http://orcid.org/0000-0001-8823-1302>, Perea-Causín, Raül, Taniguchi, Takashi, Watanabe, Kenji  <http://orcid.org/0000-0003-3701-8119>, Glazov, Mikhail M.  <http://orcid.org/0000-0003-4462-0749>, Malic, Ermin und Chernikov, Alexey  (2021) Nonclassical Exciton Diffusion in Monolayer WSe2.  Physical Review Letters 127 (7).      
relation: http://doi.org/10.1103/PhysRevLett.127.076801
relation: 10.1103/PhysRevLett.127.076801