  The effect of Rashba spin-orbit (SO) interaction on the hole states in a
quantum dot is studied in the presence of an external magnetic field. We
demonstrate here that the Rashba SO coupling has a profound effect on the
energy spectrum of the holes revealing level repulsions between the states with
the same total momentum. We also show that the resulting spin-orbit gap is much
larger than the corresponding one for the electron energy levels in a quantum
dot. Inter-hole interactions only marginally reduce the spin-orbit gap. This
enhanced Rashba effect would manifest itself in the tuneling current which
depends on the spin-orbit coupling strength.
