Jeil Jung: Layer pseudospin magnetism and electric field induced anomalous Hall effects in rhombohed

Title: Layer pseudospin magnetism and electric field induced anomalous Hall effects in rhombohedral multilayer graphene

Abstract: Recent experiments have revealed the possibility of achieving sizeable Coulomb interaction driven gapped phases in dual gated rhombohedral multilayer graphene devices where carrier densities and perpendicular electric fields can be simultaneously controlled. Of particular importance are the pentalayer and tetralayer devices whose spontaneous gaps of the order of a few tens of meV are attributable to layer pseudospin polarization of the states near the Dirac point in chiral 2DEG systems. The layer pseudospin polarization can take place in a variety of ways leading to different Hall conductivities depending on the signs of the mass terms for each one of the spin-valley flavors. By means of mean-field Hartree-Fock approach we examine and compare the self-consistent solutions corresponding to the different pseudospin magnetic phases. Addition of a spin-orbit coupling term or moire potentials are expected to sensitively alter the ground-state of the system, allowing for example to split the folded moire bands such that they are prone to CDW gaps with fractional filling densities. We comment on the energetics involved in the spontaneous spin-valley polarization when we add a finite carrier doping in the presence of perpendicular electric fields in a moire-less system.