Calculations of Universal Properties near Phase Transition Published

Nikolay V. Prokof'ev of the University of Massachusetts at Amherst reports the publication of a paper describing his group's calculations for the critical exponents for a 2-dimensional (2-D) gas of Bosons. They studied the crossover between the mean-field and critical behavior of the two-dimensional Bose gas throughout the fluctuation region of the Berezinskii--Kosterlitz--Thouless phase transition point, and established universal (for all weakly interacting symbol4 models) relations between thermodynamic parameters of the system, including superfluid and quasi-condensate densities. They also developed the mean-field theory based on the notion of a quasi-condensate, which was shown to work remarkably well outside of the fluctuation region (which now can be characterized quantitatively). Their results provide the best reference data to compare with and to study interaction effects in superfluid 2-D Bose systems.

These new results are published in "Two-Dimensional Weakly Interacting Bose Gas in the Fluctuation Region", with authors N.V. Prokof'ev and B.V. Svistunov, Phys. Rev. A 66, 043608 (2002).