Transition between ground state and metastable states in classical two-dimensional atoms

Structural and static properties of a classical two-dimensional system consisting of a finite number of charged particles that are laterally confined by a parabolic potential are investigated by Monte Carlo simulations and the Newton optimization technique. This system is the classical analog of the well-known quantum dot problem. The energies and configurations of the ground and all metastable states are obtained. In order to investigate the barriers and the transitions between the ground and all metastable states we first locate the saddle points between them, then by walking downhill from the saddle point to the different minima, we find the path in configurational space from the ground state to the metastable states, from which the geometric properties of the energy landscape are obtained. The sensitivity of the ground-state configuration on the functional form of the interparticle interaction and on the confinement potential is also investigated.