  We investigate the effect of an applied magnetic field on resonant tunneling
of electrons through the bound states of self-assembled InAs quantum dots (QDs)
embedded within an (AlGa)As tunnel barrier. At low temperatures (no more than 2
K), a magnetic field B applied either parallel or perpendicular to the
direction of current flow causes a significant enhancement of the tunnel
current. For the latter field configuration, we observe a strong angular
anisotropy of the enhanced current when B is rotated in the plane of the
quantum dot layer. We attribute this behavior to the effect of the lowered
symmetry of the QD eigenfunctions on the electron-electron interaction.
