Transport Property and Spin-Orbit Torque in 2D Rashba Ferromagnetic Electron Gas

In this paper, we investigate the spin-orbit torque and transport property in a 2D Rashba ferromagnetic electron gas. The longitudinal conductivity can be divided into two parts: the first term is determined by the charge density and is independent of the spin degrees of freedom. The second term depends on the two bands that spin in the opposite directions, and it is directly proportional to spin-orbit torque regardless of the band structure and temperature. This is a general and underlying relation between the transport property and spin-orbit torque. Moreover, we show the impacts of the spin-orbit coupling constant and Fermi energy on transverse conductivity and spin-orbit torque, which is helpful for relevant experiments.