Interplay of Lorentz-Berry forces in position-momentum spaces for valley-dependent impurity scattering in α-T_3 lattices

摘要

The Berry-phase mediated valley-selected skew scattering in alpha-T-3 lattices is demonstrated. The interplay of Lorentz and Berry forces in position and momentum spaces is revealed and analyzed. Many-body screening of the electron-impurity interaction is taken into account to avoid overestimation of back and skew scattering of electrons in the system. Triplet peak from skew interactions at two valleys is found in near-vertical and near-horizontal forward- and backward-scattering directions for small Berry phases and low magnetic fields. Magnetic-field dependence in both nonequilibrium and thermal-equilibrium currents is also presented for valleydependent longitudinal and transverse transports mediated by a Berry phase. Mathematically, two Boltzmann moment equations are employed for computing scattering-angle distributions of nonequilibrium skew currents by using microscopic inverse energy-and momentum-relaxation times. Meanwhile, a valley-dependent unbalanced thermal-equilibrium anomalous Hall current induced by the Berry force in momentum space, due to different mobilities for two valleys, is also computed for comparisons.