Theory of the inverse spin galvanic effect in quantum wells

The understanding of the fundamentals of spin and charge densities and currents interconversion by spin-orbit coupling can enable efficient applications beyond the possibilities offered by conventional electronics. For this purpose we consider various forms of the frequency-dependent inverse spin galvanic effect in semiconductor quantum wells and epilayers taking into account the cubic in the electron momentum spin-orbit coupling in the Rashba and Dresselhaus forms, concentrating on the current-induced spin polarization (CISP). We find that including the cubic terms qualitatively explains recent findings of the CISP in InGaAs epilayers being the strongest if the internal spin-orbit coupling field is the smallest and vice versa [Norman, Phys. Rev. Lett. 112, 056601 (2014)PRLTAO0031-900710.1103/PhysRevLett.112.056601; Luengo-Kovac, Phys. Rev. B 96, 195206 (2017)2469-995010.1103/PhysRevB.96.195206], in contrast to the common understanding. Our results provide a promising framework for the control of spin transport in future spintronics devices.