Correlated insulator of excitons in WSe2/WS2 moire superlattices

• 成果类型: Article
• 署名作者: Xiong, Richen; Nie, Jacob H.; Brantly, Samuel L.; Hays, Patrick; Sailus, Renee; Watanabe, Kenji; Taniguchi, Takashi; Tongay, Sefaattin; Jin, Chenhao
• 署名单位: University of California System; University of California Santa Barbara; Arizona State University; Arizona State University-Tempe; National Institute for Materials Science; National Institute for Materials Science
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-11073
• DOI: 10.1126/science.add5574
• 发表日期: 2023-05-26
• 页码: 860-864
• 关键词: interlayer excitons; mott; TRANSITION; superfluid

摘要

A panoply of unconventional electronic states has been observed in moire superlattices. Engineering similar bosonic phases remains, however, largely unexplored. We report the observation of a bosonic correlated insulator in tungsten diselenide/tungs ten disulfide (WSe2/WS2) moire superlattices composed of excitons, that is, tightly bound electron-hole pairs. We develop a pump probe spectroscopy method that we use to observe an exciton incompressible state at exciton filling nex = 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 ne = 1, suggesting a mixed correlated insulating state between the two limits. Our studies establish semiconducting moire superlattices as an intriguing platform for engineering bosonic phases.