Phase diagram of a 2D Ising model within a nonextensive approach
Centro Brasileiro de Pesquisas Físicas, Rua Dr. Xavier Sigaud 150, 22290-180 Rio de Janeiro, Brazil
2 CICECO, Universidade de Aveiro, 3810-193 Aveiro, Portugal
Revised: 5 March 2008
Published online: 19 April 2008
In this work we report Monte Carlo simulations of a 2D Ising model, in which the statistics of the Metropolis algorithm is replaced by the nonextensive one. We compute the magnetization and show that phase transitions are present for q ≠ 1. A q - phase diagram (critical temperature vs. the entropic parameter q) is built and exhibits some interesting features, such as phases which are governed by the value of the entropic index q. It is shown that such phases favors some energy levels of magnetization states. It is also shown that the contribution of the Tsallis cutoff is capital to the existence of phase transitions.
PACS: 05.90.+m – Other topics in statistical physics, thermodynamics, and nonlinear dynamical systems / 05.50.+q – Lattice theory and statistics / 05.10.Ln – Monte Carlo methods
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2008