Anisotropic magnetoresistance in multiorbital systems*

Magnetotransport is a useful probe for studying magnetism, electron-electron interactions, as well as the underlying symmetries of a crystal. We study the impact of an in-plane magnetic field on 2D multiorbital electron gases as a function of electron density, scattering length, temperature, and spin-orbit interactions. These parameters affect the shape of the different spin-split Fermi surfaces, which in turn is shown to set the amplitude of the anisotropic magnetoresistance and its dominant symmetry components. We comment on the validity of the relaxation-time approximation and the necessity to resort to the full Boltzmann equation.