Magnetic charge and ordering in kagome spin ice

TL;DR

This study explores magnetic ordering in kagome spin ice, revealing a two-stage transition with an intermediate critical phase and long-range charge order, influenced by dipolar interactions.

Contribution

It uncovers the nature of phase transitions and intermediate phases in kagome spin ice, including the role of long-range interactions and defect freeze-out.

Findings

Intermediate critical phase with Kosterlitz-Thouless transitions

Long-range magnetic charge order in dipolar spin ice

Large spin correlation length due to defect freeze-out

Abstract

We present a numerical study of magnetic ordering in spin ice on kagome, a two-dimensional lattice of corner-sharing triangles. The magnet has six ground states and the ordering occurs in two stages, as one might expect for a six-state clock model. In spin ice with short-range interactions up to second neighbors, there is an intermediate critical phase separated from the paramagnetic and ordered phases by Kosterlitz-Thouless transitions. In dipolar spin ice, the intermediate phase has long-range order of staggered magnetic charges. The high and low-temperature phase transitions are of the Ising and 3-state Potts universality classes, respectively. Freeze-out of defects in the charge order produces a very large spin correlation length in the intermediate phase. As a result of that, the lower-temperature transition appears to be of the Kosterlitz-Thouless type.