A frustrated antipolar phase analogous to classical spin liquids

TL;DR

This paper reports the discovery of an electric analogue to classical spin liquids in a triangular lattice of uniaxial electric dipoles, revealing a highly degenerate, frustrated antipolar phase with unique low-temperature dynamics.

Contribution

It introduces a new frustrated antipolar phase in EuAl12O19 that mimics classical spin liquids, expanding understanding of frustrated electric systems.

Findings

Highly degenerate antipolar state at low temperature

Absence of long-range order despite short-range correlations

Thermally activated dynamics slowing down upon cooling

Abstract

The study of magnetic frustration in classical spin systems was motivated by the prediction and discovery of classical spin liquid states. These uncommon magnetic phases are characterized by a massive degeneracy of their ground state implying a finite magnetic entropy at zero temperature. While the classical spin liquid state was originally predicted in the Ising triangular lattice antiferromagnet in 1950, this state has never been experimentally observed in any triangular magnets. We report here the discovery of an electric analogue of classical spin liquids on a triangular lattice of uniaxial electric dipoles in EuAl12O19 . This new type of frustrated antipolar phase is characterized by a highly degenerate state at low temperature implying an absence of long-range antiferroelectric order, despite short-range antipolar correlations. Its dynamics are governed by a thermally activated process, slowing down upon cooling towards a complete freezing at zero temperature.