Stochastic many-body calculations of moiré states in twisted bilayer graphene at high pressures

Abstract We introduce three developments within the stochastic many-body perturbation theory: efficient evaluation of off-diagonal self-energy terms, construction Dyson orbitals, and constrained random phase approximation. The approaches readily handle systems with thousands atoms. use them to explore electronic states twisted bilayer graphene (tBLG) characterized by giant unit cells correlated states. document formation electron localization under compression; weakly are merely shifted in energy. demonstrate how efficiently downfold subspace on a model Hamiltonian screened frequency-dependent two-body interaction. For 6° tBLG system, onsite interactions between 200 300 meV compression. orbitals exhibit spatial distribution similar mean-field single-particle Under pressure, electron-electron increase localized states; however, dynamical screening does not fully balance dominant bare Coulomb