Double-Exchange Model on Triangle Chain

TL;DR

This paper investigates the ground state phases of the double-exchange model on a triangle chain, revealing a potential chiral glass phase driven by geometric frustration and spin interactions.

Contribution

It introduces a numerical analysis of the double-exchange model on a triangle chain, highlighting the role of complex transfer integrals and spin-induced Peierls instability.

Findings

Identification of a chiral glass phase with local spin chirality

Phase diagrams showing competition among kinetic, exchange, and frustration energies

Insight into the effects of real vs. complex transfer integrals

Abstract

We study ground state properties of the double-exchange model on triangle chain in the classical limit on $t_{2g}$ spins. The ground state is determined by a competition among the kinetic energy of the $e_g$ electron, the antiferromagnetic exchange energy between the $t_{2g}$ spins, and frustration due to a geometric structure of the lattice. The phase diagrams are obtained numerically for two kinds of the models which differ only in the transfer integral being real or complex. The properties of the states are understood from the viewpoint of the spin-induced Peierls instability. The results suggest the existence of a chiral glass phase which is characterized by a local spin chirality and a continuous degeneracy.