Inversion symmetry breaking in noncollinear magnetic phase of a triangular lattice antiferromagnet CuFeO2

TL;DR

This study investigates how noncollinear magnetic phases in CuFeO2 induce electric polarization, revealing the crucial role of noncollinear spin structures in magnetoelectric effects within frustrated triangular lattice antiferromagnets.

Contribution

It demonstrates that noncollinear magnetic phases in CuFeO2 break inversion symmetry and induce electric polarization, highlighting the importance of noncollinear spin structures in magnetoelectric phenomena.

Findings

Finite electric polarization occurs only in noncollinear magnetic phases.

Noncollinear spin structures break inversion symmetry in CuFeO2.

Frustrated magnets with noncollinear configurations are potential magnetoelectric candidates.

Abstract

Magnetoelectric and magnetoelastic phenomena correlated with a phase transition into noncollinear magnetic phase have been investigated for single crystals of CuFeO2 with a frustrated triangular lattice. CuFeO2 exhibits several long-wavelength magnetic structures related to the spin frustration, and it is found that finite electric polarization, namely inversion symmetry breaking, occurs with noncollinear but not at collinear magnetic phases. This result demonstrates that the noncollinear spin structure is a key role to induce electric polarization, and suggests that frustrated magnets which often favor noncollinear configurations can be plausible candidates for magnetoelectrics with strong magnetoelectric interaction.