Effects of the presence of Cs impurities on the two-dimensional 4He phase diagram

Abstract

The changes in the two-dimensional (2D) 4He phase diagram due to the introduction of impurities (Cs atoms) are estimated using path-integral Monte Carlo simulations. Our results indicate that when we increase the concentration of Cs atoms, the liquid-gas coexistence zone decreases in size and eventually disappears for ¿Cs~0.005Å-2, so that 2D 4He gases will be stable at low temperatures.