Spin transport of a doped Mott insulator in moiré heterostructures
Moiré superlattices of semiconducting transition metal dichalcogenide heterobilayers are model systems for investigating strongly correlated electronic phenomena. Specifically, WSe<sub>2</sub>/WS<sub>2</sub> moiré superlattices have emerged as a quantum simulator for the two-dimensional extended Hubbard model. Experimental studies of charge transport have revealed correlated Mott insulator and generalized Wigner crystal states, but spin transport of the moiré heterostructure has not yet been sufficiently explored. Here, we use spatially and temporally resolved circular dichroism spectroscopy to directly image the spin transport as a function of carrier doping and temperature in WSe<sub>2</sub>/WS<sub>2</sub> moiré heterostructures. We observe diffusive spin transport at all hole concentrations at 11 Kelvin - including the Mott insulator at one hole per moiré unit cell - where charge transport is strongly suppressed. At elevated temperatures the spin diffusion constant remains unchanged in the Mott insulator state, but it increases significantly at finite doping away from the Mott state. The doping- and temperature-dependent spin transport can be qualitatively understood using a t-J model, where spins can move via the hopping of spin-carrying charges and via the exchange interaction.
Authors
- Danqing Wang (ORCID: https://orcid.org/0000-0002-7369-1944)
- Liang Fu (ORCID: https://orcid.org/0009-0008-1000-2903)
- Jacob H. Nie
- Emma C. Regan (ORCID: https://orcid.org/0000-0002-9100-6031)
- Alex K. Zettl (ORCID: https://orcid.org/0000-0001-6330-136X)
- Sefaattin Tongay (ORCID: https://orcid.org/0000-0001-8294-984X)
- Takashi Taniguchi (ORCID: https://orcid.org/0000-0002-1467-3105)
- Kenji Watanabe (ORCID: https://orcid.org/0000-0003-3701-8119)
- Feng Wang (ORCID: https://orcid.org/0000-0001-8369-6194)
- Trithep Devakul (ORCID: https://orcid.org/0000-0002-4129-897X)
- Yang Zhang (ORCID: https://orcid.org/0000-0003-4630-5056)
- Wenyu Zhao (ORCID: https://orcid.org/0000-0003-3365-621X)
- Zuocheng Zhang (ORCID: https://orcid.org/0000-0001-7851-6101)
- Zheyu Lu
Institutions
- Lawrence Berkeley National Laboratory (US)
- University of California, Santa Barbara (US)
- National Institute for Materials Science (JP)
- Kavli Energy NanoScience Institute (US)
- Arizona State University (US)
- Massachusetts Institute of Technology (US)
- University of Tennessee at Knoxville (US)
- University of California, Berkeley (US)
Publication Details
- Journal
- Nature Communications
- Published
- 2024-11-26
- DOI
- https://doi.org/10.1038/s41467-024-54633-z
- Citations
- 4
- Primary Topic
- 2D Materials and Applications
- Type
- article
- Field-Weighted Citation Impact
- 0.47
Funders
- National Science Foundation
- U.S. Department of Energy
- Massachusetts Institute of Technology
- Office of Science
- Japan Society for the Promotion of Science
- Division of Materials Research
- Division of Civil, Mechanical and Manufacturing Innovation
- Basic Energy Sciences