  We study the spin Hall effect of a two-dimensional electron gas in the
presence of a magnetic field and both the Rashba and Dresselhaus spin-orbit
interactions. We show that the value of the spin Hall conductivity, which is
finite only if the Zeeman spin splitting is taken into account, may be tuned by
varying the ratio of the in-plane and out-of-plane components of the applied
magnetic field. We identify the origin of this behavior with the different role
played by the interplay of spin-orbit and Zeeman couplings for in-plane and
out-of-plane magnetic field components.
