Thermally-Induced Phases on a Kagome Lattice

Abstract

In this chapter, we consider an Ising-spin Kondo lattice model on a kagome lattice. The model shares some of the fundamental characters with the triangular model considered in Chaps. 3 and 4; both the triangular and kagome lattices consist of triangular units, and the two models show geometrical frustration when the nearest-neighbor interaction is antiferromagnetic. We show that this kagome lattice model exhibits a rich phase diagram with various thermally-induced phases: loop-liquid state, \(\sqrt{3}\times \sqrt{3}\) partially-disordered state, and partial ferromagnetic state. Among these phases, loop-liquid state is a novel ferrimagnetic state, which possesses a fractional magnetic moment but the system remains disordered due to thermal fluctuations. We also discuss the similarity and differences of the partially-disordered state in kagome and triangular lattice models.