  Spin current of two-dimensional holes occupying the ground-state subband in
an asymmetric quantum well and interacting with static disorder potential is
calculated in the presence of a weak magnetic field H perpendicular to the well
plane. Both spin-orbit coupling and Zeeman coupling are taken into account. It
is shown that the applied electric field excites both the transverse
(spin-Hall) and diagonal spin currents, the latter changes its sign at a finite
H and becomes greater than the spin-Hall current as H increases. The effective
spin-Hall conductivity introduced to describe the spin response in Hall bars is
considerably enhanced by the magnetic field in the case of weak disorder and
demonstrates a non-monotonic dependence on H.
