Beyond the maximum density droplet: From few-electron to many-electron quantum dots in strong magnetic fields

Using the method of breaking of circular symmetry and of subsequent symmetry restoration via projection techiques, we present calculations for the ground-state energies and excitation spectra of $N$-electron parabolic quantum dots in strong magnetic fields in the medium-size range $10 \leq N \leq 30$. The physical picture suggested by our calculations is that of non-rigid rotating Wigner molecules (RWM's) comprising multiple rings, with the rings rotating independently of each other. A quasi-classical expression for the energetics of such non-rigid multi-ring RWM's is derived; it is applicable to arbitrary sizes given the corresponding equilibrium configuration of classical point charges.