CT- Orbital magnetism and Fermi surface reconstructions near half filling in twisted bilayer graphene

Abstract

Magic-angle twisted bilayer graphene (MATBG) exhibits a wide variety of correlated phases, spanning from insulating to superconducting and magnetic states, favored by the flat bands. The degeneracy among closely competing ground states can be lifted by polarizing spin and valley degrees of freedom; hence, the four-fold degeneracy of the low-energy electrons has a significant impact on the underlying mechanism governing the correlated phases at different band fillings. The overall phase diagram of MATBG is remarkably sensitive to external perturbations such as carrier density, electromagnetic field, pressure, temperature, and dielectric environments. Despite this unprecedented tunability, a complete understanding of the observed phases has remained elusive. In our recent study, we conducted magneto-transport measurements on MATBG proximitized by a layer of tungsten diselenide, thereby introducing finite spin-orbit coupling into the system. Our findings unveiled an anomalous Hall effect ...