Physical review. B, Condensed matter
Determination of multicritcal points for lattice-gas models by finite-size scaling of the susceptibility
Per Arne Rikvold
Abstract
The finite-size scaling properties of the susceptibility ${\ensuremath{\chi}}_{N}$ with respect to the nonordering field and the ``second correlation length'' \ensuremath{\xi}${^}_{N}$ for a lattice-gas system of strip width N are related by a sum-rule argument, and used to determine multicritical temperatures. For a simple system, the estimates based on ${\ensuremath{\chi}}_{N}$ and \ensuremath{\xi}${^}_{N}$ are consistent. ${\ensuremath{\chi}}_{N}$ depends only on the largest eigenvalue of the transfer matrix and provides improved estimates for a model whose eigenvalue spectrum is too complicated to guarantee accurate determination of \ensuremath{\xi}${^}_{N}$, which depends on the ratio of the largest and third largest eigenvalues.