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Updated: Jan 7, 2026

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
Published on: May 27, 2020
Giant enhancement of exciton diffusion near an electronic Mott insulator
Pranshoo Upadhyay1, Daniel G Suárez-Forero1,2, Tsung-Sheng Huang1
1Joint Quantum Institute, University of Maryland, College Park, MD, USA.
Abstract:
Bose-Fermi mixtures can be realized in semiconductor heterostructures, with bosons as excitons and fermions as dopant charges. However, the complexity of these hybrid systems challenges understanding of the mechanisms that determine properties such as mobility. We investigated interlayer exciton diffusion in tungsten diselenide-tungsten disulfide heterobilayers at ultralow exciton density and low temperatures to examine how charges affect exciton mobility. Near the electronic Mott insulator phase, we observed a giant thousand-fold enhancement of exciton diffusion relative to charge neutrality. We attribute this to mobile valence holes, which experienced a suppressed moiré potential due to charge order and recombined nonmonogamously with conduction electrons. Our results show exciton diffusion as a probe of correlated electron states and Bose-Fermi interplay.
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