Magnetic phases from competing Hubbard and extended Coulomb interactions in twisted bilayer graphene

We implement a self-consistent Hartree-Fock approximation based on microscopic model in real space, which allows us to consider the interplay between Hubbard and extended Coulomb interaction twisted bilayer graphene at magic angle. These two interactions tend favor different symmetry breaking patterns, having therefore complementary roles regimes where one or other dominates. show that, for sufficiently large values of on-site repulsion, angle has an antiferromagnetic ground state charge neutrality point, while half-filling lowest valence band becomes fully spin-polarized. In general, suitable screening is required observe magnetic either case, as otherwise instabilities take place sector, preferentially form time-reversal, chiral valley breaking.