THE EFFECT OF AN UNEVEN POTENTIAL ON THE FEW-ELECTRON SPECTRUM IN A QUANTUM-DOT

In a quasi-2D model of a quantum dot in a magnetic field, which includes the effects of spin, we consider what happens to the two-particle spectrum when a cosine perturbation along the x and y axes is added to a fundamentally parabolic confinement potential. Such a corrugation in the potential may arise, for example, due to the discrete nature of the positive background charges which are normally modelled as jellium. We find that this potential is capable of giving rise to a shift in the location of the singlet/triplet crossing to lower values of magnetic field which is consistent with the tendency seen in experiment.