Spectroscopy of Twisted Bilayer Graphene Correlated Insulators
arXiv:2110.15300 · doi:10.1103/PhysRevLett.129.117602
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 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 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.
8+80 pages, 2+65 figures. New version matches the published version
References in corpus (15)
- Flat Bands in Slightly Twisted Bilayer Graphene
- AC conductivity of graphene: from tight-binding model to 2+1-dimensional quantum electrodynamics
- Spectral and Fermi surface properties from Wannier interpolation
- Theory of interacting electrons on the honeycomb lattice
- Band structure and insulating states driven by the Coulomb interaction in twisted bilayer graphene
- Visualizing Broken Symmetry and Topological Defects in a Quantum Hall Ferromagnet
- Experimental evidence of chiral symmetry breaking in Kekulé-ordered graphene
- Structure of twisted and buckled bilayer graphene
- Global Phase Diagram of the Normal State of Twisted Bilayer Graphene
- Imaging tunable quantum Hall broken-symmetry orders in graphene
- Competing phases of interacting electrons on triangular lattices in moiré heterostructures
- Topological zero modes and Dirac points protected by spatial symmetry and chiral symmetry
- Valley magnetism, nematicity, and density wave orders in twisted bilayer graphene
- A modular ultra-high vacuum millikelvin scanning tunneling microscope
- Local density of states and scanning tunneling currents in graphene
Cited by in corpus (29)
- Quantum textures of the many-body wavefunctions in magic-angle graphene
- A Microscopic Perspective on Moiré Materials
- Imaging inter-valley coherent order in magic-angle twisted trilayer graphene
- Magic-angle helical trilayer graphene
- Phonons in magic-angle twisted bilayer graphene
- Dynamical correlations and order in magic-angle twisted bilayer graphene
- Detecting symmetry breaking in magic angle graphene using scanning tunneling microscopy
- Local Kekulé distortion turns twisted bilayer graphene into topological Mott insulators and superconductors
- Kekulé spiral order in magic-angle graphene: a density matrix renormalization group study
- Spin skyrmion gaps as signatures of strong-coupling insulators in magic-angle twisted bilayer graphene
- Electron-phonon coupling and competing Kekulé orders in twisted bilayer graphene
- Electron-K-Phonon Interaction In Twisted Bilayer Graphene
- Moiré optical phonons dancing with heavy electrons in magic-angle twisted bilayer graphene
- Electron phonon coupling in the topological heavy fermion model of twisted bilayer graphene
- Kekulé spirals and charge transfer cascades in twisted symmetric trilayer graphene
- Topological heavy fermions in magnetic field
- Nematic versus Kekulé phases in twisted bilayer graphene under hydrostatic pressure
- Atomistic theory of moiré Hofstadter's butterfly in magic-angle graphene
- Textured Exciton Insulators
- Twisted bilayer graphene reveals its flat bands under spin pumping
- Anderson's theorem for correlated insulating states in twisted bilayer graphene
- Chern-Textured Exciton Insulators with Valley Spiral Order in Moiré Materials
- Understanding Symmetry Breaking in Twisted Bilayer Graphene from Cluster Constraints
- Ferromagnetism vs. Antiferromagnetism in Narrow-Band Systems: Competition Between Quantum Geometry and Band Dispersion
- Mean-field Modelling of Moiré Materials: A User's Guide with Selected Applications to Twisted Bilayer Graphene
- Quantization and quantum oscillations of the sublattice charge order in Dirac insulators
- Robustness of real-space topology in moiré systems
- Surface acoustic wave-driven valley current generation in intervalley coherent states
- Prediction of the Hubbard U parameter from scanning tunneling microscopy images of moire systems using image recognition