Frustration-induced Dodecamer Ordering in the Double-Exchange Spin Ice Model on the Kagom\'e Lattice

TL;DR

This paper explores how frustration-induced dodecamer cluster ordering occurs in a double-exchange spin ice model on the kagomé lattice, revealing complex phase transitions and residual degeneracy at low temperatures.

Contribution

It demonstrates the formation of dodecamer clusters and discusses the potential for larger multiple-site cluster orderings in frustrated systems.

Findings

Spin ice state forms at intermediate temperatures.

Dodecamer phase emerges at lower temperatures.

Residual macroscopic degeneracy persists in the dodecamer phase.

Abstract

We investigate a detail of a dodecamer cluster ordering in a double-exchange spin ice model on a kagom\'e lattice. In frustrated systems, ordinary spin orderings are suppressed and macroscopic degeneracy remains down to low temperatures. In some frustrated systems, the degeneracy is lifted due to residual interactions and cluster orderings are stabilized. In the present model, the spin ice state is first formed at intermediate temperatures, and further entropies are released at lower temperatures as the dodecamer phase emerges. Since the spin symmetry is not broken in the dodecamer phase, there still exists macroscopic degeneracy. At further low temperatures, a possible spin ordering due to inter-dodecamer interactions is proposed. We discuss that such a multiple-site clustering larger than a bond-pair might be generic to frustrated systems where macroscopic degeneracy is lifted by residual interactions.