Phenomenological model for magnetotransport in a multi-orbital system

By means of the Boltzmann equation, we have calculated some magnetotransport quantities for the layered multi-orbital compound Sr${}_2$RuO${}_4$. The Hall coefficient, the magnetoresistance and the in-plane resistivity have been determined taking into account the Fermi surface curvature and different time collisions for the electrons in the $t_{2g}$ bands. A consistent explanation of the experimental results has been obtained assuming different relaxation rates for the in-plane transport with and without an applied magnetic field, respectively.