Spin superfluidity in noncollinear antiferromagnets

TL;DR

This paper investigates spin superfluidity in noncollinear antiferromagnets, demonstrating its theoretical basis, potential experimental signatures, and suggesting iron jarosites as candidate materials for realization.

Contribution

It provides a theoretical framework for spin superfluidity in three-sublattice antiferromagnets with approximate U(1) symmetry, including effects of Dzyaloshinskii-Moriya interactions.

Findings

Spin superfluidity exhibits power-law decay in nonlocal measurements.

Approximate U(1) symmetry persists despite symmetry-breaking interactions.

Iron jarosites are proposed as candidate materials for experimental realization.

Abstract

We explore the spin superfluid transport in exchange interaction dominated three-sublattice antiferromagnets. The system in the long-wavelength regime is described by an $SO(3)$ invariant field theory. Additional corrections from Dzyaloshinskii-Moriya interactions or anisotropies can break the symmetry; however, the system still approximately holds a $U(1)$-rotation symmetry. Thus, the power-law spatial decay signature of spin superfluidity is identified in a nonlocal-measurement setup where the spin injection is described by the generalized spin-mixing conductance. We suggest iron jarosites as promising material candidates for realizing our proposal.