Antisymmetric Spin Interaction in Metals

Abstract

The bilinear term of the spin-polarization density in the spin-dependent energy of metals is separated into the terms of the symmetric spin interaction (SSI) and of the antisymmetric spin interaction (ASI), whose properties are first investigated phenomenologically. A microscopic derivation of the SSI and ASI is given for a metal which has no inversion center. It is shown that the spin-orbit coupling which splits electronic bands in the absence of inversion center produces an antisymmetric component of the wave-vector-dependent susceptibility and the ASI is proportional to the antisymmetric component to the first order of the latter quantity. The obtained ASI energy is concluded to be not always small compared with the SSI energy.