Spectroscopy signatures of electron correlations in a trilayer graphene/hBN moiré superlattice
Name
2202.12330.pdf
Description
Accepted version
Size
2.45 MB
Format
Adobe PDF
Checksum (MD5)
003003b79a9524687632851c6c61c86f
Author(s)
Yang, Jixiang
Chen, Guorui
Han, Tianyi
Zhang, Qihang
Zhang, Ya-Hui
Jiang, Lili
Lyu, Bosai
Li, Hongyuan
Watanabe, Kenji
Taniguchi, Takashi
Date Issued
March 18, 2022
Journal
Science
Publisher
American Association for the Advancement of Science (AAAS)
Citation
Yang, Jixiang, Chen, Guorui, Han, Tianyi, Zhang, Qihang, Zhang, Ya-Hui et al. 2022. "Spectroscopy signatures of electron correlations in a trilayer graphene/hBN moiré superlattice." Science, 375 (6586).
Version
Author's final manuscript
Abstract
ABC-stacked trilayer graphene/hexagonal boron nitride moiré superlattice (TLG/hBN) has emerged as a playground for correlated electron physics. We report spectroscopy measurements of dual-gated TLG/hBN using Fourier transform infrared photocurrent spectroscopy. We observed a strong optical transition between moiré minibands 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 milli–electron volts, 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.
MIT Department
Massachusetts Institute of Technology. Department of Physics
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Creative Commons Attribution-Noncommercial-Share Alike
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DOI of Published Version
https://doi.org/10.1126/science.abg3036
