Spectroscopy of Twisted Bilayer Graphene Correlated Insulators
| Autor: | Călugăru, Dumitru, Regnault, Nicolas, Oh, Myungchul, Nuckolls, Kevin P., Wong, Dillon, Lee, Ryan L., Yazdani, Ali, Vafek, Oskar, Bernevig, B. Andrei |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Phys. Rev. Lett. 129, 117602, 8 September 2022 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevLett.129.117602 |
| Popis: | We analytically compute the scanning tunneling microscopy (STM) signatures of integer-filled correlated ground states of the magic angle twisted bilayer graphene (TBG) narrow bands. After experimentally validating the strong-coupling approach at $\pm 4$ electrons/moir\'e unit cell, we consider the spatial features of the STM signal for 14 different many-body correlated states and assess the possibility of Kekul\'e distortion (KD) emerging at the graphene lattice scale. Remarkably, we find that coupling the two opposite graphene valleys in the intervalley-coherent (IVC) TBG insulators does not always result in KD. As an example, we show that the Kramers IVC state and its nonchiral $\mathrm{U} \left( 4 \right)$ rotations do not exhibit any KD, while the time-reversal-symmetric IVC state does. Our results, obtained over a large range of energies and model parameters, show that the STM signal and Chern number of a state can be used to uniquely determine the nature of the TBG ground state. Comment: 8+80 pages, 2+65 figures. New version matches the published version |
| Databáze: | arXiv |
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