Moiré lattice effects on the orbital magnetic response of twisted bilayer graphene and Condon instability
arXiv:2103.13459 · doi:10.1103/PhysRevB.103.224436
Abstract
We analyze the orbital magnetic susceptibility from the band structure of twisted bilayer graphene. Close to charge neutrality, the out-of-plane susceptibility inherits the strong diamagnetic response from graphene. Increasing the doping, a crossover from diamagnetism to paramagnetism is obtained and a logarithmic divergence develops at the van Hove singularity of the Moiré lattice in the first band. The enhanced paramagnetism at the van Hove singularity is stronger for relatively large angle but gets suppressed by the flat spectrum towards the vicinity of the first magic angle. A diverging paramagnetic susceptibility indicates an instability towards orbital ferromagnetism with an orbital out-of-plane magnetization and a Landau level structure. The region of instability is however found to be practically very small, parametrically suppressed by the ratio of the electron velocity to the speed of light. We also discuss the in-plane orbital susceptibility at charge neutrality where we find a paramagnetic response and a logarithmic divergence at the magic angle. The paramagnetic response is associated with negative counterflow current in the two layers and does not admit a semiclassical description.
19 pages, 13 figures
References in corpus (19)
- Flat Bands in Slightly Twisted Bilayer Graphene
- Lattice relaxation and energy band modulation in twisted bilayer graphenes
- Orbital magnetization in periodic insulators
- Strongly Correlated Chern Insulators in Magic-Angle Twisted Bilayer Graphene
- Quantum Theory of Orbital Magnetization and its Generalization to Interacting Systems
- Twisted bilayer graphene. II. Stable symmetry anomaly
- Theory of Photon Condensation in a Spatially-Varying Electromagnetic Field
- Twisted bilayer graphene I. Matrix elements, approximations, perturbation theory and a 2-Band model
- Linear response of doped graphene sheets to vector potentials
- Chiral response of twisted bilayer graphene
- Diamagnetism in disordered graphene
- Chiral Approximation to Twisted Bilayer Graphene: Exact Intra-Valley Inversion Symmetry, Nodal Structure and Implications for Higher Magic Angles
- Competing orders at higher-order Van Hove points
- Orbital magnetism of coupled bands models
- f-Sum Rule and Unconventional Spectral Weight Transfer in Graphene
- Many-body orbital paramagnetism in doped graphene sheets
- Spectral characterization of magic angles in twisted bilayer graphene
- Parquet renormalization group analysis of weak-coupling instabilities with multiple high-order Van Hove points inside the Brillouin zone
- Orbital susceptibility of T-graphene: Interplay of high-order van Hove singularities and Dirac cones
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- First-order photon condensation in magnetic cavities: A two-leg ladder model
- In-plane orbital magnetization as a probe for symmetry breaking in strained twisted bilayer graphene
- Revisiting the magnetic responses of bilayer graphene from the perspective of the quantum distance
- Superradiant Quantum Phase transition for Landau Polaritons with Rashba and Zeeman couplings
- Neutral magic-angle bilayer graphene: Condon instability and chiral resonances
- Atomistic theory of moiré Hofstadter's butterfly in magic-angle graphene
- Optical response of alternating twisted trilayer graphene
- Collective magnetic excitations in AA- and AB-stacked graphene bilayers
- Layer-Resolved Quantum Transport in Twisted Bilayer Graphene: Counterflow and Machine Learning Predictions
- Paramagnetic singularities of the orbital magnetism in graphene with a moiré potential