Pade approximant calculation of the singularity in the magnetic susceptibility of an ising square lattice
A.V. Ferris-Prabhu
Abstract
The Pade approximant method w a s applied to Clapp's spinspin correlation formulation for the magnetic susceptibility in an Ising square lattice, in order to investigate the nature of the critical point.For the exact cluster formulation it is found that as the cluster size increases, the critical point, namely the point at which the susceptibility has a singularity, approaches Onsager's exact value of 0.414, and that ~( t ) -?/( tt c ) .For the selfconsistent formulation, twenty Pade approximants were calculated.The value of the critical point converged very rapidly to 0.41862770 and it was found that X ( t ) l/(tt c ) .