Correlated interlayer exciton insulator in heterostructures of monolayer WSe2 and moiré WS2/WSe2
- Univ. of California, Berkeley, CA (United States)
- Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). Materials Sciences Division
- Arizona State Univ., Tempe, AZ (United States)
- National Institute for Materials Science (NIMS), Tsukuba (Japan)
- Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). Materials Sciences Division; Kavli Energy NanoScience Institute, Berkeley, CA (United States)
Moiré superlattices in van der Waals heterostructures have emerged as a powerful tool for engineering quantum phenomena. Here, in this work, we report the observation of a correlated interlayer exciton insulator in a double-layer heterostructure composed of a WSe2 monolayer and a WS2/WSe2 moiré bilayer that are separated by ultrathin hexagonal boron nitride. The moiré WS2/WSe2 bilayer features a Mott insulator state when the density of holes is one per moiré lattice site. When electrons are added to the Mott insulator in the WS2/WSe2 moiré bilayer and an equal number of holes are injected into the WSe2 monolayer, a new interlayer exciton insulator emerges with the holes in the WSe2 monolayer and the electrons in the doped Mott insulator bound together through interlayer Coulomb interactions. The interlayer exciton insulator is stable up to a critical hole density in the WSe2 monolayer, beyond which the interlayer exciton dissociates. Our study highlights the opportunities for realizing quantum phases in double-layer moiré systems due to the interplay between the moiré flat band and strong interlayer electron interactions.
- Research Organization:
- Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division (MSE); US Army Research Office (ARO); USDOD; National Science Foundation (NSF)
- Grant/Contract Number:
- AC02-05CH11231; SC0020653; W911NF-17-1-0312; CMMI-1933214; 1935994; 1904716; DMR-1552220; DMR-1955889
- OSTI ID:
- 1994334
- Journal Information:
- Nature Physics, Vol. 18, Issue 10; ISSN 1745-2473
- Publisher:
- Nature Publishing Group (NPG)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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