  For spin-3/2 holes the anisotropic part of the instantaneous Luttinger
Hamiltonian can be represented as an effective quadrupole coupling. We
investigate the hole spin relaxation process induced by nonadiabatic
fluctuations of this interaction. The obtained analytical solution of the
stochastic Liouville equation describes the polarization decay of spin-3/2
holes in all regimes of momentum scattering: from collision-dominated to
ballistic. Our results create the basis for quantitative interpretation of
recent experiments and elucidate the striking difference between the hole spin
relaxation process in bulk crystals and 2D semiconductor nanostructures.
