Anisotropic current-induced spin accumulation in the two-dimensional electron gas with spin-orbit coupling

We investigate the magnetoelectric (or inverse spin-galvanic) effect in the two-dimensional electron gases with both Rashba and Dresselhaus spin-orbit couplings using an exact solution of the Boltzmann equation for electron spin and momentum. The spin response to an in-plane electric field turns out to be highly anisotropic, while the usual charge conductivity remains isotropic, contrary to earlier statements.

Figure 1

Spin accumulation (in arbitrary units) vs direction of the electric field in polar coordinates for different Rashba and Dresselhaus constants: A, $\alpha =3\beta$; B, $\alpha =2.15\beta$; C, $\alpha =\beta$. Curve B corresponds to the real situation in $n$-type InAs (Ref. 18).