  Epitaxial semiconductor nanowires with charge carrier holes can exhibit an
infinite mass of holes and spin-locking due to chiral spectrum linear in
momentum and spin. The criterion for emergence of topological superconductivity
and Majorana fermions in these wires coupled to an s-type superconductors is
the same as in topological insulators, and opposite to the criterion of onset
of Majorana modes in quantum wires with parabolic spectrum in the presence of
spin-orbit interactions.
