Giant enhancement of exciton diffusion near an electronic Mott insulator

Science 2026 Open access

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Authors: Pranshoo Upadhyay, Daniel G. Suarez-Forero, Tsung-Sheng Huang, Mahmoud Jalali Mehrabad, Beini Gao, Supratik Sarkar, Deric Session, Kenji Watanabe, Takashi Taniguchi, Y. M. Zhou, Michael Knap, Mohammad Hafezi
DOI: 10.1126/science.ads5266
Cited by: 7
References: 54

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.

Fields of Study & Subjects

2D Materials and Applications Organic and Molecular Conductors Research Electronic and Structural Properties of Oxides

Publication details

Journal / source
Science
Publisher
American Association for the Advancement of Science (AAAS)
Volume
391
Issue
6783
Pages
394–398
Publication date
1 January 2026
Language
EN