Competing broken-symmetry and rotationally symmetric spin-singlet states in a few-electron quantum dot in a magnetic field

On the basis of developed variational many-body approach, within a second quantized formulation, the nature of the ground state of a few-electron system in a parabolic two-dimensional (2D) quantum dot (QD) is theoretically investigated. The resulting analytical expressions lead to various phase transitions: spin singlet, maximum density droplet, Wigner phase, etc. in a broad range of magnetic fields and QD confinement potentials. A first investigation of a broken-symmetry spin-singlet phase in a QD in a magnetic field is shown to be an important application of the proposed technique.