Non-universal critical behaviour of a mixed-spin Ising model on the extended Kagome lattice

Jozef Strecka; Lucia Canova

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Non-universal critical behaviour of a mixed-spin Ising model on the extended Kagome lattice

Jozef Strecka·Lucia Canova

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Abstract

The mixed spin-1/2 and spin-3/2 Ising model on the extended Kagomé lattice is solved by establishing a mapping correspondence with the eight-vertex model. Letting the parameter of uniaxial single-ion anisotropy tend to infinity, the model becomes exactly soluble as a free-fermion eight-vertex model. Under this restriction, the critical points are characterized by critical exponents from the standard Ising universality class. In a certain subspace of interaction parameters that corresponds to a coexistence surface between two ordered phases, the model becomes exactly soluble as a symmetric zero-field eight-vertex model. This surface is bounded by a line of bicritical points that have non-universal interaction-dependent critical exponents.

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BibTeX RIS

Jozef Strecka, Lucia Canova. 2006-03-31. Non-universal critical behaviour of a mixed-spin Ising model on the extended Kagome lattice. https://arxiv.org/abs/cond-mat/0507366

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