Fermi Pressure and Coulomb Repulsion Driven Rapid Hot Plasma Expansion in a van der Waals Heterostructure
Artikel i vetenskaplig tidskrift, 2023

Transition metal dichalcogenide heterostructures provide a versatile platform to explore electronic and excitonic phases. As the excitation density exceeds the critical Mott density, interlayer excitons are ionized into an electron-hole plasma phase. The transport of the highly non-equilibrium plasma is relevant for high-power optoelectronic devices but has not been carefully investigated previously. Here, we employ spatially resolved pump-probe microscopy to investigate the spatial-temporal dynamics of interlayer excitons and hot-plasma phase in a MoSe2/WSe2 twisted bilayer. At the excitation density of ∼1014 cm-2, well exceeding the Mott density, we find a surprisingly rapid initial expansion of hot plasma to a few microns away from the excitation source within ∼0.2 ps. Microscopic theory reveals that this rapid expansion is mainly driven by Fermi pressure and Coulomb repulsion, while the hot carrier effect has only a minor effect in the plasma phase.

van der Waals heterostructure

MoSe 2

exciton

WSe 2

transition metal dichalcogenides

Författare

Junho Choi

University of Texas

Jacob Embley

University of Texas

Daria D. Blach

Purdue University

Raul Perea Causin

Chalmers, Fysik, Kondenserad materie- och materialteori

Daniel Erkensten

Chalmers, Fysik, Kondenserad materie- och materialteori

Dong Seob Kim

University of Texas

Long Yuan

Purdue University

Woo Young Yoon

University of Texas

Takashi Taniguchi

National Institute for Materials Science (NIMS)

Kenji Watanabe

National Institute for Materials Science (NIMS)

Keiji Ueno

Saitama University

Emanuel Tutuc

University of Texas

Samuel Brem

Philipps-Universität Marburg

Ermin Malic

Philipps-Universität Marburg

Chalmers, Fysik, Kondenserad materie- och materialteori

Xiaoqin Li

University of Texas

Libai Huang

Purdue University

Nano Letters

1530-6984 (ISSN) 1530-6992 (eISSN)

Vol. 23 10 4399-4405

Graphene Core Project 3 (Graphene Flagship)

Europeiska kommissionen (EU) (EC/H2020/881603), 2020-04-01 -- 2023-03-31.

Ämneskategorier (SSIF 2011)

Atom- och molekylfysik och optik

Fusion, plasma och rymdfysik

Den kondenserade materiens fysik

DOI

10.1021/acs.nanolett.3c00678

Mer information

Senast uppdaterat

2025-05-28