Excitonic Mott insulator in a Bose-Fermi-Hubbard system of moiré WS2/WSe2 heterobilayer
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- University of Maryland, College Park, MD (United States). Joint Quantum Institute (JQI); OSTI
- University of Maryland, College Park, MD (United States). Joint Quantum Institute (JQI)
- University of Maryland, College Park, MD (United States)
- National Institute for Materials Science (NIMS), Tsukuba (Japan)
- Eidgenoessische Technische Hochschule (ETH), Zurich (Switzerland)
- University of Maryland, College Park, MD (United States). Joint Quantum Institute (JQI); Eidgenoessische Technische Hochschule (ETH), Zurich (Switzerland)
Understanding the Hubbard model is crucial for investigating various quantum many-body states and its fermionic and bosonic versions have been largely realized separately. Recently, transition metal dichalcogenides heterobilayers have emerged as a promising platform for simulating the rich physics of the Hubbard model. In this work, we explore the interplay between fermionic and bosonic populations, using a WS2/WSe2 heterobilayer device that hosts this hybrid particle density. We independently tune the fermionic and bosonic populations by electronic doping and optical injection of electron-hole pairs, respectively. This enables us to form strongly interacting excitons that are manifested in a large energy gap in the photoluminescence spectrum. The incompressibility of excitons is further corroborated by observing a suppression of exciton diffusion with increasing pump intensity, as opposed to the expected behavior of a weakly interacting gas of bosons, suggesting the formation of a bosonic Mott insulator. We explain our observations using a two-band model including phase space filling. Our system provides a controllable approach to the exploration of quantum many-body effects in the generalized Bose-Fermi-Hubbard model.
- Research Organization:
- University of Maryland, College Park, MD (United States)
- Sponsoring Organization:
- National Science Foundation (NSF); US Air Force Office of Scientific Research (AFOSR); US Army Research Laboratory (USARL); US Department of the Navy, Office of Naval Research (ONR); USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division (MSE)
- Grant/Contract Number:
- SC0022885
- OSTI ID:
- 2472288
- Journal Information:
- Nature Communications, Journal Name: Nature Communications Journal Issue: 1 Vol. 15; ISSN 2041-1723
- Publisher:
- Nature Publishing GroupCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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