Abstract
The dynamical phase transition of the two-dimensional (2D) electric dipole systems with a background screening charge has been investigated via molecular dynamics simulations. In the simulations three cases of the screening strength, including the bare dipole-dipole interactions, have been examined. In the case where the screening is absent, the quasi-long-range behavior of the bare dipole-dipole interaction potential was handled by implementing the extension of the Wolf method, the gradient shifted force electrostatics. This method enables to efficiently reduce the computational cost of the simulations to with the number of dipoles in the system. The effect of the screening on the course of the solid – liquid phase transitions has been analyzed in detail via the track of the orientational order parameters and polygon order parameter. Results show that the solid – liquid phase transition points of the system occur at lower values of the temperature, or larger values of coupling parameter, due to the screening. We observe that the shift of the melting and freezing points to lower values of the temperature becomes considerable as the strength of the screening is increased.