Dirac spectroscopy of strongly correlated phases in twisted trilayer graphene

被引:0
作者
Cheng Shen
Patrick J. Ledwith
Kenji Watanabe
Takashi Taniguchi
Eslam Khalaf
Ashvin Vishwanath
Dmitri K. Efetov
机构
[1] ICFO—Institut de Ciencies Fotoniques,Department of Physics
[2] The Barcelona Institute of Science and Technology,Fakultät für Physik
[3] Castelldefels,undefined
[4] Harvard University,undefined
[5] National Institute for Materials Science,undefined
[6] Ludwig-Maximilians-Universität,undefined
[7] Munich Center for Quantum Science and Technology (MCQST),undefined
来源
Nature Materials | 2023年 / 22卷
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摘要
Magic-angle twisted trilayer graphene (MATTG) hosts flat electronic bands, and exhibits correlated quantum phases with electrical tunability. In this work, we demonstrate a spectroscopy technique that allows for dissociation of intertwined bands and quantification of the energy gaps and Chern numbers C of the correlated states in MATTG by driving band crossings between Dirac cone Landau levels and energy gaps in the flat bands. We uncover hard correlated gaps with C = 0 at integer moiré unit cell fillings of ν = 2 and 3 and reveal charge density wave states originating from van Hove singularities at fractional fillings ν = 5/3 and 11/3. In addition, we demonstrate displacement-field-driven first-order phase transitions at charge neutrality and ν = 2, which are consistent with a theoretical strong-coupling analysis, implying C2T symmetry breaking. Overall, these properties establish a diverse electrically tunable phase diagram of MATTG and provide an avenue for investigating other related systems hosting both steep and flat bands.
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页码:316 / 321
页数:5
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