Layer Hall counterflow as a model probe of magic-angle twisted bilayer graphene

Abstract

The recent constructions of flat moiré minibands in specifically twisted multilayer graphene and twisted transition metal dichalcogenides (TMDs) have facilitated the observation of strong correlations with a convenient tunability. These correlations in flat bands result in the band dispersion heavily influenced by carrier densities, leading to filling-dependent quasiparticle band renormalizations. Particularly, in magic-angle twisted bilayer graphene (MATBG), the band structure--including the quasiparticle energy and wavefunction--is crucial in understanding the correlated properties. Previous theoretical studies have demonstrated the presence of a time-reversal-even charge Hall counterflow in response to a direct current (DC) electric field in twisted bilayers as chiral structures. In this study, we show that such layer Hall counterflow can serve as a sensitive probe for MATBG model parameters, which are currently ambiguous as a result of unavoidable structural relaxation and twist-angle disorder. We present the layer Hall counterflow and the associated in-plane magnetization for three different MATBG continuum models, based on which many-body interacting models have been widely applied to study strong correlations in MATBG. At the single-particle level, our findings indicate notable differences in layer-projected Hall conductivity, both in magnitude and sign, between different MATBG continuum models. Furthermore, our self-consistent Hartree calculations, performed on each of these single-particle continuum models, reveal renormalized layer-projected Hall conductivity by the self-consistent Hartree field.

References in corpus (13)

• Moiré heterostructures as a condensed matter quantum simulator
• The crucial role of atomic corrugation on the flat bands and energy gaps of twisted bilayer graphene at the "magic angle" $\theta \sim 1.08^{\circ }$
• Chiral response of twisted bilayer graphene
• Structure of twisted and buckled bilayer graphene
• Optical and plasmonic properties of twisted bilayer graphene: Impact of interlayer tunneling asymmetry and ground-state charge inhomogeneity
• Pseudo-magnetic fields, particle-hole asymmetry, and microscopic effective continuum Hamitonians of twisted bilayer graphene
• Theory of tunable flux lattices in the homobilayer moiré of twisted and uniformly strained transition metal dichalcogenides
• Continuum effective Hamiltonian for graphene bilayers for an arbitrary smooth lattice deformation from microscopic theories
• Time-Reversal Even Charge Hall Effect from Twisted Interface Coupling
• Truncated atomic plane wave method for the subband structure calculations of Moiré systems
• Theory of plasmonic edge states in chiral bilayer systems
• Theory of Optical Activity in Doped Systems with Application to Twisted Bilayer Graphene
• Optical activity and transport in twisted bilayer graphene: the essence of spatial dispersion effects

Cited by in corpus (5)

• Twistronics and moiré superlattice physics in 2D transition metal dichalcogenides
• Colossal Layer Nernst Effect in Twisted Moiré Layers
• Orbital Magnetization of Correlated States in Twisted Bilayer Transition Metal Dichalcogenides
• Layer-Resolved Quantum Transport in Twisted Bilayer Graphene: Counterflow and Machine Learning Predictions
• Interlayer electric multipole Hall effect in twisted multilayers