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The critical Ising lines of the d=2 Ashkin-Teller model

G. Kamieniarz·P. Kozlowski·R. Dekeyser
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Abstract

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 (AT) model on the square lattice. A leading-order expansion of the ratio $Q$ in the presence of a non-vanishing thermal field is found from finite-size scaling and the corresponding expression is fitted to the accurate perturbative transfer-matrix data calculations for the $L\times L$ square clusters with $L\leq 9$.

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G. Kamieniarz, P. Kozlowski, R. Dekeyser. 1998-03-23. The critical Ising lines of the d=2 Ashkin-Teller model. https://doi.org/10.1103/physreve.55.3724

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