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 includ es the effects of spin, we consider what happens to the two-particle s pectrum 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 t he positive background charges which are normally modelled as jellium. We find that this potential is capable of giving rise to a shift in t he location of the singlet/triplet crossing to lower values of magneti c field which is consistent with the tendency seen in experiment.