Applied Sciences (May 2021)

Superfluid Transition and Specific Heat of the 2D <i>x</i>-<i>y</i> Model: Monte Carlo Simulation

  • Phong H. Nguyen,
  • Massimo Boninsegni

Journal volume & issue
Vol. 11, no. 11
p. 4931


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We present results of large-scale Monte Carlo simulations of the 2D classical x-y model on the square lattice. We obtain high accuracy results for the superfluid fraction and for the specific heat as a function of temperature, for systems of size L×L with L up to 212. Our estimate for the superfluid transition temperature is consistent with those furnished in all previous studies. The specific heat displays a well-defined peak, whose shape and position are independent of the size of the lattice for L>28, within the statistical uncertainties of our calculations. The implications of these results on the interpretation of experiments on adsorbed thin films of 4He are discussed.