Wednesday, February 13, 2013

1302.2900 (Yun-Da Hsieh et al.)

Finite-size scaling method for the Berezinskii-Kosterlitz-Thouless
transition
   [PDF]

Yun-Da Hsieh, Ying-Jer Kao, A. W. Sandvik
We present an improved finite-size scaling method for reliably extracting the critical temperature T_BKT of a Berezinskii-Kosterlitz-Thouless (BKT) transition. Using the known Weber-Minhagen multiplicative logarithmic correction to the spin stiffness rho_s at T_BKT and the Kosterlitz-Nelson relation between the transition temperature and the stiffness, rho_s(T_BKT)=2T_BKT/pi, we define a size dependent transition temperature T_ BKT(L_1,L_2) based on a pair of system sizes L1, L2, e.g., L_2=2L1. We use Monte Carlo data for the standard two-dimensional classical XY model to demonstrate that this quantity is well behaved, rapidly convergent, and can be reliably extrapolated to the thermodynamic limit, L_1,L_2 -> infinity. Using GPU (graphical processing unit) computing, we obtain high-precision data for L up to 512 and extract a transition temperature T_BKT=0.89274(1), where the statistical error, +/- 1, in the last digit is about 6 times smaller than that of the best previous estimate.
View original: http://arxiv.org/abs/1302.2900

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