Magnetoanisotropy of electron-correlation-enhanced tunneling through a quantum dot

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 $(\ensuremath{\leqslant}2\phantom{\rule{0.3em}{0ex}}\mathrm{K})$, a magnetic field $\mathbf{B}$ 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 $\mathbf{B}$ 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.