Anomalously slow hot carrier cooling and insulator-to-metal transition in a photo-doped Mott insulator
Abstract Photo-doped Mott insulators can exhibit novel photocarrier transport and relaxation dynamics and non-equilibrium phases. However, time-resolved real-space imaging of these processes are still lacking. Here, we use scanning ultrafast electron microscopy (SUEM) to directly visualize the spatial-temporal evolution of photoexcited species in a spin-orbit assisted Mott insulator α -RuCl 3 . At low optical fluences, we observe extremely long hot photocarrier transport time over one nanosecond, almost an order of magnitude longer than any known values in conventional semiconductors. At higher optical fluences, we observe nonlinear features suggesting a photo-induced insulator-to-metal transition, which is unusual in a large-gap Mott insulator. Our results demonstrate the rich physics in a photo-doped Mott insulator that can be extracted from spatial-temporal imaging and showcase the capability of SUEM to sensitively probe photoexcitations in strongly correlated electron systems.
Authors
- Ryan Gnabasik (ORCID: https://orcid.org/0000-0002-4026-4954)
- Usama Choudhry (ORCID: https://orcid.org/0000-0002-7694-5022)
- Basamat S. Shaheen (ORCID: https://orcid.org/0000-0001-6969-1389)
- Yujie Quan (ORCID: https://orcid.org/0000-0003-1299-1801)
- Jiaqiang Yan (ORCID: https://orcid.org/0000-0001-6625-4706)
- Ángel Rubio (ORCID: https://orcid.org/0000-0003-2060-3151)
- Kenneth S. Burch (ORCID: https://orcid.org/0000-0002-7541-0245)
- Bolin Liao (ORCID: https://orcid.org/0000-0002-0898-0803)
- Jin Zhang (ORCID: https://orcid.org/0000-0001-7830-3464)
- Kewen Huang (ORCID: https://orcid.org/0009-0006-7081-188X)
- Emma Low (ORCID: https://orcid.org/0009-0005-5348-0305)
Institutions
- Boston College (US)
- Oak Ridge National Laboratory (US)
- University of California, Santa Barbara (US)
- Universität Hamburg (DE)
- University of the Basque Country (ES)
- Chinese Academy of Sciences (CN)
- National Center for Nanoscience and Technology (CN)
- Center for Free-Electron Laser Science (DE)
- Max Planck Institute for the Structure and Dynamics of Matter (DE)
- Flatiron Health (United States) (US)
- Flatiron Institute (US)
Publication Details
- Journal
- Communications Physics
- Published
- 2025-05-02
- DOI
- https://doi.org/10.1038/s42005-025-02107-z
- Primary Topic
- Advanced Condensed Matter Physics
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- U.S. Department of Energy
- Office of Science
- U.S. Air Force
- Air Force Office of Scientific Research
- Army Research Office