Abstract

Moiré systems such as magic-angle twisted bilayer graphene have attracted significant attention due to their ability to host correlated phenomena including superconductivity and strongly correlated insulating states. By defining the single-particle Green’s function in the band basis, this work systematically develops a many-body perturbation theory framework to address correlations beyond mean-field Hartree-Fock approaches. As a specific example, twisted bilayer graphene is analyzed within Hartree-Fock, including analytical solutions for symmetry-breaking states at integer fillings and the finite-temperature metal-insulator transition, and then extended with self-consistent GW corrections to study ring-diagram effects and electronic compressibility.

Abstract

Moiré systems such as magic-angle twisted bilayer graphene have attracted significant attention due to their ability to host correlated phenomena including superconductivity and strongly correlated insulating states. By defining the single-particle Green’s function in the band basis, this work systematically develops a many-body perturbation theory framework to address correlations beyond mean-field Hartree-Fock approaches. As a specific example, twisted bilayer graphene is analyzed within Hartree-Fock, including analytical solutions for symmetry-breaking states at integer fillings and the finite-temperature metal-insulator transition, and then extended with self-consistent GW corrections to study ring-diagram effects and electronic compressibility.

Abstract

Moiré systems such as magic-angle twisted bilayer graphene have attracted significant attention due to their ability to host correlated phenomena including superconductivity and strongly correlated insulating states. By defining the single-particle Green’s function in the band basis, this work systematically develops a many-body perturbation theory framework to address correlations beyond mean-field Hartree-Fock approaches. As a specific example, twisted bilayer graphene is analyzed within Hartree-Fock, including analytical solutions for symmetry-breaking states at integer fillings and the finite-temperature metal-insulator transition, and then extended with self-consistent GW corrections to study ring-diagram effects and electronic compressibility.

Abstract

Moiré systems such as magic-angle twisted bilayer graphene have attracted significant attention due to their ability to host correlated phenomena including superconductivity and strongly correlated insulating states. By defining the single-particle Green’s function in the band basis, this work systematically develops a many-body perturbation theory framework to address correlations beyond mean-field Hartree-Fock approaches. As a specific example, twisted bilayer graphene is analyzed within Hartree-Fock, including analytical solutions for symmetry-breaking states at integer fillings and the finite-temperature metal-insulator transition, and then extended with self-consistent GW corrections to study ring-diagram effects and electronic compressibility.