Thermodynamic behavior of correlated electron-hole fluids in van der Waals heterostructures

Ruishi Qi; Andrew Y. Joe; Zuocheng Zhang; Yongxin Zeng; Tiancheng Zheng; Qixin Feng; Jingxu Xie; Emma Regan; Zheyu Lu; Takashi Taniguchi; Kenji Watanabe; Sefaattin Tongay; Michael F. Crommie; Allan H. MacDonald; Feng Wang

doi:10.1038/s41467-023-43799-7

論文 Thermodynamic behavior of correlated electron-hole fluids in van der Waals heterostructures

Ruishi Qi ; Andrew Y. Joe ; Zuocheng Zhang ; Yongxin Zeng ; Tiancheng Zheng ; Qixin Feng ; Jingxu Xie ; Emma Regan ; Zheyu Lu ; Takashi Taniguchi (National Institute for Materials Science) ; Kenji Watanabe (National Institute for Materials Science) ; Sefaattin Tongay ; Michael F. Crommie ; Allan H. MacDonald ; Feng Wang

Download file (1.51MB)
Download as zip (991KB)

コレクション

引用

Ruishi Qi, Andrew Y. Joe, Zuocheng Zhang, Yongxin Zeng, Tiancheng Zheng, Qixin Feng, Jingxu Xie, Emma Regan, Zheyu Lu, Takashi Taniguchi, Kenji Watanabe, Sefaattin Tongay, Michael F. Crommie, Allan H. MacDonald, Feng Wang. Thermodynamic behavior of correlated electron-hole fluids in van der Waals heterostructures. Nature Communications. 2023, 14 (1), 8264. https://doi.org/10.1038/s41467-023-43799-7

(BibTeX)

説明:

(abstract)

Coupled two-dimensional electron-hole bilayers provide a unique platform to study strongly correlated Bose-Fermi mixtures in condensed matter. Electrons and holes in spatially separated layers can bind to form interlayer excitons, composite Bosons expected to support excitonic insulators and high-temperature exciton superfluids. The interlayer excitons can also interact strongly with excess charge carriers when electron and hole densities are unequal. Here, we use optical spectroscopy to quantitatively probe the local thermodynamic properties of strongly correlated electron-hole fluids in MoSe2/hBN/WSe2 heterostructures. We observe a discontinuity in the electron and hole chemical potentials at matched electron and hole densities, a definitive signature of an excitonic insulator ground state. The exciton insulator is stable up to a Mott density of ~0.8×1012 cm-2 and has a thermal ionization temperature of ~70 K. The density dependence of the electron, hole, and exciton chemical potentials reveals strong correlation effects across the phase diagram. Compared with a non-interacting uniform charge distribution, the correlation effects lead to significant attractive exciton-exciton and exciton-charge interactions in the electron-hole fluid. Our work highlights the unique quantum behavior that can emerge in strongly correlated electron-hole systems.

権利情報: