Effect of Zero Point Motion on Solidification of Quantum Particles

Abstract

Phase diagram of quantum particles adsorbed on a periodic substrate is studied by means of the path integral Monte Carlo method. Interaction potential between particles is assumed to be a hardcore-like (r⁻¹²-potential) one or the Lennard–Jones potential. The density is fixed to a commensurate one. When the hardcore diameter is large, the system solidifies from a gas phase at a finite temperature. By changing the mass of particles, the magnitude of the zero point motion is changed. It is found that the system solidifies at a higher temperature as the mass becomes lighter, i.e., the zero point motion promotes the solidification of particles.