@article{0a82ce3cb85a48dc9529d676b03001d5,
title = "Spectroscopy of Twisted Bilayer Graphene Correlated Insulators",
abstract = "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 ±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 U(4) 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.",
author = "Dumitru Cǎlugǎru and Nicolas Regnault and Myungchul Oh and Nuckolls, {Kevin P.} and Dillon Wong and Lee, {Ryan L.} and Ali Yazdani and Oskar Vafek and Bernevig, {B. Andrei}",
note = "Funding Information: We thank Fang Xie for fruitful discussions. The simulations presented in this work were performed using the Princeton Research Computing resources at Princeton University, which is a consortium of groups led by the Princeton Institute for Computational Science and Engineering (PICSciE) and Office of Information Technology{\textquoteright}s Research Computing. B. A. B. and N. R. were supported by the Office of Naval Research (ONR Grant No. N00014-20-1-2303), National Science Foundation (EAGER Grant No. DMR 1643312), a Simons Investigator grant (No. 404513), the BSF Israel US foundation (Grant No. 2018226), the Gordon and Betty Moore Foundation through Grant No. GBMF8685 towards the Princeton theory program, the Gordon and Betty Moore Foundation{\textquoteright}s EPiQS Initiative (Grant No. GBMF11070), and a Guggenheim Fellowship from the John Simon Guggenheim Memorial Foundation. B. A. B. and N. R. were also supported by the NSF-MRSEC (Grant No. DMR-2011750), and the Princeton Global Network Funds. B. A. B. and N. R. gratefully acknowledge financial support from the Schmidt DataX Fund at Princeton University made possible through a major gift from the Schmidt Futures Foundation. This work is also partly supported by a project that has received funding from the European Research Council (ERC) under the European Union{\textquoteright}s Horizon 2020 research and innovation programme (Grant Agreement No. 101020833). O. V. is supported by NSF DMR-1916958 and by the Gordon and Betty Moore Foundation{\textquoteright}s EPiQS Initiative Grant No. GBMF11070. This work was also supported by the Gordon and Betty Moore Foundation{\textquoteright}s EPiQS initiative grants GBMF9469 and DOE-BES Grant No. DE-FG02-07ER46419 to A. Y. Other support for the experimental work was provided by NSF-MRSEC through the Princeton Center for Complex Materials NSF-DMR-2011750, NSF-DMR-1904442, ExxonMobil through the Andlinger Center for Energy and the Environment at Princeton, and the Princeton Catalysis Initiative. We are grateful to K. Watanabe and T. Taniguchi for providing high-quality hexagonal boron nitride crystals used for the experimental work. A. Y. acknowledges the hospitality of the Aspen Center for Physics, which is supported by National Science Foundation Grant No. PHY-1607611. Publisher Copyright: {\textcopyright} 2022 American Physical Society.",
year = "2022",
month = sep,
day = "9",
doi = "10.1103/PhysRevLett.129.117602",
language = "English (US)",
volume = "129",
journal = "Physical Review Letters",
issn = "0031-9007",
publisher = "American Physical Society",
number = "11",
}