A set of exactly solvable Ising models with half-odd-integer spin

Onofre Rojas; S. M. de Souza

doi:10.1016/j.physleta.2009.02.020

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arXiv · 0805.0572

A set of exactly solvable Ising models with half-odd-integer spin

Onofre Rojas·S. M. de Souza

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Abstract

We present a set of exactly solvable Ising models, with half-odd-integer spin-S on a square-type lattice including a quartic interaction term in the Hamiltonian. The particular properties of the mixed lattice, associated with mixed half-odd-integer spin-(S,1/2) and only nearest-neighbour interaction, allow us to map this system either onto a purely spin-1/2 lattice or onto a purely spin-S lattice. By imposing the condition that the mixed half-odd-integer spin-(S,1/2) lattice must have an exact solution, we found a set of exact solutions that satisfy the {\it free fermion} condition of the eight vertex model. The number of solutions for a general half-odd-integer spin-S is given by $S+1/2$. Therefore we conclude that this transformation is equivalent to a simple spin transformation which is independent of the coordination number.

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Onofre Rojas, S. M. de Souza. 2009-04-23. A set of exactly solvable Ising models with half-odd-integer spin. https://doi.org/10.1016/j.physleta.2009.02.020

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