On Precursors of Topological Phase Transitions of Interacting Particles Confined in a Disk

Equilibrium configurations of one-component charge particles confined in a disk potential are analyzed at zero temperatures. With the increase of the particle number the hexagonal structure of equilibrium configurations breaks, giving rise to the nucleation of defects. One of the central issues is to identify conditions for the nucleation of the hexatic phase in such systems, which is accompanied by the appearance of defects in the Wigner crystalline phase. A joint orientation-translational correlation analysis of structural changes, occurring with an increase of the number of particles, elucidates the precursors of the onset of the hexatic phase in the considered system.