  We present a theoretical study of ac charge transport arising from adiabatic
temporal variation of zero-field spin splitting in a quasi-onedimensional hole
system (realized, e.g., in a quantum wire or point contact). As in
conduction-electron systems, part of the current results from spin-dependent
electromotive forces. We find that the magnitude of this current contribution
is two orders of magnitude larger for holes and exhibits parametric dependences
that make it more easily accessible experimentally. Our results suggest hole
structures to be good candidates for realizing devices where spin currents are
pumped by time-varying electric fields.
