Giant enhancement of exciton diffusion near an electronic Mott insulator.
Saved in:
| Title: | Giant enhancement of exciton diffusion near an electronic Mott insulator. |
|---|---|
| Authors: | Upadhyay, Pranshoo (AUTHOR), Suárez-Forero, Daniel G. (AUTHOR), Huang, Tsung-Sheng (AUTHOR), Mehrabad, Mahmoud Jalali (AUTHOR), Gao, Beini (AUTHOR), Sarkar, Supratik (AUTHOR), Session, Deric (AUTHOR), Watanabe, Kenji (AUTHOR), Taniguchi, Takashi (AUTHOR), Zhou, You (AUTHOR), Knap, Michael (AUTHOR), Hafezi, Mohammad (AUTHOR) |
| Source: | Science. 1/22/2026, Vol. 391 Issue 6783, p394-398. 5p. |
| Subjects: | Exciton theory, Heterostructures, Tungsten, Quantum phase transitions, Transport theory |
| 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. Editor's summary: Two-dimensional (2D) bilayer transitional metal dichalcogenides can be used to study the physics of excitons, bound states of electrons and holes, with each layer contributing either electrons or holes exclusively. These excitons, which have a bosonic nature, are immersed in a sea of electrons, which are fermions, forming a Bose-Fermi mixture. To explore how excitons behave in correlated electronic environments, Upadhyay et al. used a tungsten diselenide—tungsten disulfide moiré heterostructure and used space- and time-resolved techniques to study diffusing interlayer excitons. The researchers gated the sample to vary electron doping and found large variations of exciton diffusion across the various collective phases formed in the system. —Jelena Stajic [ABSTRACT FROM AUTHOR] |
| Copyright of Science is the property of American Association for the Advancement of Science and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Psychology and Behavioral Sciences Collection |
|
Full text is not displayed to guests.
Login for full access.
|
|
| 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. Editor's summary: Two-dimensional (2D) bilayer transitional metal dichalcogenides can be used to study the physics of excitons, bound states of electrons and holes, with each layer contributing either electrons or holes exclusively. These excitons, which have a bosonic nature, are immersed in a sea of electrons, which are fermions, forming a Bose-Fermi mixture. To explore how excitons behave in correlated electronic environments, Upadhyay et al. used a tungsten diselenide—tungsten disulfide moiré heterostructure and used space- and time-resolved techniques to study diffusing interlayer excitons. The researchers gated the sample to vary electron doping and found large variations of exciton diffusion across the various collective phases formed in the system. —Jelena Stajic [ABSTRACT FROM AUTHOR] |
|---|---|
| ISSN: | 00368075 |
| DOI: | 10.1126/science.ads5266 |
