  Based on standard k.p (8 x 8) multiband Hamiltonian, we have deduced an
explicit analytical expression for the Rashba-coupling parameter which
clarifies its anomalous behavior for heavy holes (hh), gated in
quasi-two-dimensional (Q2D) systems, by letting grow the density. Our modelling
remarkable better agrees with experimental results in comparison with earlier
theoretical models, while recovers the expected cubic dependence on the
quasi-momentum. For quasi-one-dimensional (Q1D) hh systems, we have formally
derived an effective Rashba Hamiltonian with two competitive terms on the
quasi-momentum, a linear term and a cubic one as predicted from suitable
approximations to the Q2D scope. The Rashba-coupling parameters also behave
anomalously and qualitatively support recent experiments in core/shell
nanowires. Furthermore, they exhibit an essential asymptotic discontinuity in
the low density regime as a function of the lateral confinement length. For hh,
we present closed schemes to accurately quote the Rashba-coupling parameters
both for the Q2D and Q1D systems, which become unprecedented for holes.
