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Spectroscopy Signatures of Electron Correlations in a Trilayer Graphene/hBN Moir\'e Superlattice by Yang, Jixiang; Chen, Guorui; Han, Tianyi; Zhang, Qihang; Zhang, Ya-Hui; Jiang, Lili; Lyu, Bosai; Li, Hongyuan; Watanabe, Kenji; Taniguchi, Takashi; Shi, Zhiwen; Senthil, Todadri; Zhang, Yuanbo; Wang, Feng; Ju, Long is a scholarly article available to read on EtoBox.

What is Spectroscopy Signatures of Electron Correlations in a Trilayer Graphene/hBN Moir\'e Superlattice about?

ABC-stacked trilayer graphene/hBN moir\'e superlattice (TLG/hBN) has emerged as a playground for correlated electron physics. We report spectroscopy measurements of dual-gated TLG/hBN using Fourier transformed infrared photocurrent spectroscopy. We observed a strong optical transition between moir\'e mini-bands that narrows continuously as a bandgap is opened by gating, indicating a reduction of the single particle bandwidth. At half-filling of the valence flat band, a broad absorption peak emerges at ~18 meV, indicating direct optical excitation across an emerging Mott gap. Similar photocurrent spectra are observed in two other correlated insulating states at quarter- and half-filling of the first conduction band. Our findings provide key parameters of the Hubbard model for the understanding of electron correlation in TLG/hBN.

Author

Yang, Jixiang; Chen, Guorui; Han, Tianyi; Zhang, Qihang; Zhang, Ya-Hui; Jiang, Lili; Lyu, Bosai; Li, Hongyuan; Watanabe, Kenji; Taniguchi, Takashi; Shi, Zhiwen; Senthil, Todadri; Zhang, Yuanbo; Wang, Feng; Ju, Long

Published

2022

Language

EN