Spin Hall magnetoresistance and spin Nernst magnetothermopower in a Rashba system: role of the inverse spin galvanic effect

In ferromagnet/normal-metal bilayers, the sensitivity of the spin Hall magnetoresistance and the spin Nernst magnetothermopower to the boundary conditions at the interface is of central importance. In general, such boundary conditions can be substantially affected by current-induced spin polarizations. In order to quantify the role of the latter, we consider a Rashba two-dimensional electron gas with a ferromagnet attached to one side of the system. The geometry of such a system maximizes the effect of current-induced spin polarization on the boundary conditions, and the spin Hall magnetoresistance is shown to acquire a non-trivial and asymmetric dependence on the magnetization direction of the ferromagnet. The spin Nernst magnetothermopower turns out to be very small due to a cancellation of electrical and thermal contributions, and it vanishes completely in the limit of infinite spin mixing conductance if Elliott-Yafet spin relaxation is neglected. Our findings deviate substantially from the results of previous theoretical considerations based on phenomenological drift-diffusion equations.^1
1S. Tölle, M. Dzierzawa, U. Eckern, and C. Gorini, arXiv:1708.03165