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Title: Spectroscopy of Twisted Bilayer Graphene Correlated Insulators
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/moiré unit cell, we consider the spatial features of the STM signal for 14 different many-body correlated states and assess the possibility of Kekulé 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.  more » « less
Award ID(s):
1916958
PAR ID:
10481944
Author(s) / Creator(s):
; ; ; ; ; ; ; ;
Publisher / Repository:
American Physical Society
Date Published:
Journal Name:
Physical Review Letters
Volume:
129
Issue:
11
ISSN:
0031-9007
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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