Theory of structural phase transitions in a trapped Coulomb crystal

Crystalline confined systems of charges exhibit structural phase transitions as a function of the anisotropy of the confining potential. A theory which describes these structural transitions is presented. The theory is based on the transitions which occur in infinite homogeneous 1D and 2D systems. These transitions have been previously explored for 1D systems but not for 2D systems. The charge density in the inhomogeneous crystal is found using a fluid theory as well as a theory which keeps correlations in the local density approximation.