Physical review. B, Condensed matter
Critical field and low-temperature critical indices of the ferromagnetic Ising model
Chanchal K. Majumdar, Indira Ramarao
Abstract
For the ferromagnetic Ising model the low-temperature series expansion with temperature grouping polynomials is studied. We show that certain roots of these polynomials converge to the critical field ${H}_{c}$, and in favorable cases we can determine the critical field quite accurately. Knowing the critical field ${H}_{c}$, one can determine the asymptotic behavior of the temperature grouping polynomials numerically. The essential feature is a power-law behavior. Hence, the low-temperature critical indices ${\ensuremath{\alpha}}^{\ensuremath{'}}$, $\ensuremath{\beta}$, and ${\ensuremath{\gamma}}^{\ensuremath{'}}$ can be determined. The values are in general agreement with those found by Pad\'e analysis. A critique of the accuracy of the method and its possibilities is given.