Numerical modeling of structural transitions in few-particle confined 2D systems

We study classical strongly correlated few-particle systems in two-dimensional traps. Strong interaction between the particles leads to formation of ordered structure (the Wigner crystal), and the precise configuration of particles is determined by the shape of the confinement. Structural transitions in systems of four to seven particles induced by compression of the confining trap in one of two lateral directions are modeled numerically using the statistical Monte Carlo technique and distributed (grid) computing. We focus on the dependence of the specific heat on the eccentricity of the confinement, and show that rapid variations of the specific heat can be used to detect and classify changes of system configuration. These structural transitions are the finite-size analogues of phase transitions commonly defined for infinite systems.