The Ising transition lines of the symmetric Ashkin-Teller model

J. Zittartz

Marcio Jose Martins, J. R. Drugowich de Felício

The author shows that the two-dimensional N-colour Ashkin-Teller model exhibits an Ising-like continuous transition line in the region where the model has two phase transitions. The result is also valid for the antiferromagnetic ordering. In addition they present results which support the conjecture of Grest and Widom (1981) about the location of the disorder point.

Yacine Aoun, Moritz Dober, Alexander Glazman

Smain Bekhechi, A. Benyoussef, Abdallah El Kenz +2 more

G. Kamieniarz, Piotr Kozłowski, Raf Dekeyser

The universal critical point ratio Q is exploited to determine positions of the critical Ising transition lines on the phase diagram of the Ashkin-Teller model on the square lattice. A leading-order expansion of the ratio Q in the presence of a nonvanishing thermal field is found from finite-size scaling and the corresponding expression is fitted by the accurate perturbative transfer-matrix data calculations for the L\ifmmode\times\else\texttimes\fi{}L square clusters with L\ensuremath{\leqslant}9.

Franco Strocchi