  Hole spins have gained considerable interest in the past few years due to
their potential for fast electrically controlled qubits. Here, we study holes
confined in Ge hut wires, a so far unexplored type of nanostructure. Low
temperature magnetotransport measurements reveal a large anisotropy between the
in-plane and out-of-plane g-factors of up to 18. Numerical simulations verify
that this large anisotropy originates from a confined wave function which is of
heavy hole character. A light hole admixture of less than 1% is estimated for
the states of lowest energy, leading to a surprisingly large reduction of the
out-of-plane g-factors. However, this tiny light hole contribution does not
influence the spin lifetimes, which are expected to be very long, even in non
isotopically purified samples.
