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arXiv · 2207.10764

Correlated insulator of excitons in WSe2/WS2 moiré superlattices

Richen Xiong·Jacob H. Nie·Samuel L. Brantly·Patrick Hays·Renee Sailus·Kenji Watanabe·Takashi Taniguchi·Sefaattin Tongay·Chenhao Jin
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Abstract

A panoply of unconventional electronic states has been observed in moiré superlattices. Engineering similar bosonic phases remains, however, largely unexplored. We report the observation of a bosonic correlated insulator in WSe2/WS2 moiré superlattices composed of excitons, i.e., tightly bound electron-hole pairs. We develop a pump probe spectroscopy method that we use to observe an exciton incompressible state at exciton filling ν_ex = 1 and charge neutrality, indicating a correlated insulator of excitons. With varying charge density, the bosonic correlated insulator continuously transitions into an electron correlated insulator at charge filling ν_e = 1, suggesting a mixed correlated insulating state between the two limits. Our studies establish semiconducting moiré superlattices as an intriguing platform for engineering bosonic phases.

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Richen Xiong, Jacob H. Nie, Samuel L. Brantly, Patrick Hays, Renee Sailus, Kenji Watanabe, Takashi Taniguchi, Sefaattin Tongay, Chenhao Jin. 2023-05-14. Correlated insulator of excitons in WSe2/WS2 moiré superlattices. https://doi.org/10.1126/science.add5574

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