  By means of a multiband effective mass Hamiltonian, a theoretical
characterization of the effect of the geometrical features of the confinement
profile --in particular, a longitudinal groove-- on the subbands dispersion and
spin-related properties of a rectangular HgTe/CdTe nanowire is presented.
Through an external electric field applied perpendicular to the wire, the
interplay of the induced Rashba spin splitting and these geometrical features
is investigated. It is found that by exploiting this interplay a rich
complexity of the subband structure arises, permitting the generation and
modulation of spin-polarized currents without magnetic fields.
