Soluble kagome Ising model in a magnetic field

Phys Rev E Stat Nonlin Soft Matter Phys. 2005 Apr;71(4 Pt 2):046120. doi: 10.1103/PhysRevE.71.046120. Epub 2005 Apr 18.

Abstract

An Ising model on the kagome lattice with super-exchange interactions is solved exactly under the presence of a nonzero external magnetic field. The model generalizes the super-exchange model introduced by Fisher in 1960 and is analyzed in light of a free-fermion model. We deduce the critical condition and present detailed analyses of its thermodynamic and magnetic properties. The system is found to exhibit a second-order transition with logarithmic singularities at criticality.