  Magnetization measurements of a Mn12mda wheel single-molecule magnet with a
spin ground state of S = 7 show resonant tunneling and quantum phase
interference, which are established by studying the tunnel rates as a function
of a transverse field applied along the hard magnetization axis.
Dzyaloshinskii-Moriya (DM) exchange interaction allows the tunneling between
different spin multiplets. It is shown that the quantum phase interference of
these transitions is strongly dependent on the direction of the DM vector.
