FINITE-SIZE EFFECTS IN THE QUASI-2-DIMENSIONAL ISING-MODEL

In the quasi-two-dimensional Ising model a nearest neighbour spin pair interacts with strength J (> 0) in the xy-plane and with lambdaJ (0 less-than-or-equal-to lambda << 1) in the z-axis. It shows crossover from two-dimensional to three-dimensional behaviour as the critical point is approached. We study the finite-size effects of the phenomenon by using a Monte Carlo method with the multi-spin coding technique. We derive the finite-size scaling form of the critical temperature defined as the peak position of the specific heat. It is consistent with the Monte Carlo results.