The temperature dependent thermal vector potential in spinor Boltzmann equation

The thermal scalar and vector potential were introduced to investigate the thermal transport under a temperature gradient in terms of linear response theory[1,2]. However, the microscopic origin of these phenomenological thermal potentials had not been addressed clearly. In this manuscript, we try to derive a temperature dependent damping force based on the spinor Boltzmann equation (SBE), and relate it with the thermal gauge potential, which is exactly the temperature dependent thermal scalar and vector potential. It is shown that the thermal potential originates from the scattering of conduction electrons and impurity or other scattering mechanisms. We also derive a temperature dependent inverse relaxation time, which depends on momentum, it is different from the usual constant relaxation time. We evaluate the temperature dependent damping force by an approximated analytical solution of SBE. The other physical observable such as charge current and spin current are also explored.