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Q-Dependent Susceptibilities in Ferromagnetic Quasiperiodic Z-Invariant Ising Models

Helen Au-Yang·Jacques H. H. Perk
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Abstract

We study the q-dependent susceptibility chi(q) of a series of quasiperiodic Ising models on the square lattice. Several different kinds of aperiodic sequences of couplings are studied, including the Fibonacci and silver-mean sequences. Some identities and theorems are generalized and simpler derivations are presented. We find that the q-dependent susceptibilities are periodic, with the commensurate peaks of chi(q) located at the same positions as for the regular Ising models. Hence, incommensurate everywhere-dense peaks can only occur in cases with mixed ferromagnetic-antiferromagnetic interactions or if the underlying lattice is aperiodic. For mixed-interaction models the positions of the peaks depend strongly on the aperiodic sequence chosen.

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Helen Au-Yang, Jacques H. H. Perk. 2006-12-29. Q-Dependent Susceptibilities in Ferromagnetic Quasiperiodic Z-Invariant Ising Models. https://doi.org/10.1007/s10955-006-9213-9

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