Topological Effects on Quantum Phase Slips in Superfluid Spin Transport

TL;DR

This paper explores how quantum fluctuations and topological effects influence the decay of superfluid spin currents in antiferromagnetic spin chains, highlighting differences between integer and half-odd-integer spins and proposing an experimental verification method.

Contribution

It introduces a theoretical analysis of topological effects on quantum phase slips in superfluid spin transport, emphasizing the role of the topological term in the nonlinear sigma model.

Findings

Quantum fluctuations cause decay of spin supercurrent via phase slips.

Topological term differentiates decay rates between integer and half-odd-integer spins.

Proposes an experimental setup to measure spin decay dependence on spin type.

Abstract

We theoretically investigate effects of quantum fluctuations on superfluid spin transport through easy-plane quantum antiferromagnetic spin chains in the large-spin limit. Quantum fluctuations give rise to decaying of spin supercurrent by unwinding the magnetic order parameter within the easy plane, which is referred to as phase slips. We show that the topological term in the nonlinear sigma model for the spin chains qualitatively differentiates decaying rate of the spin supercurrent between integer spin and half-odd-integer spin chains. An experimental setup for a magnetoelectric circuit is proposed, in which the dependence of the decaying rate on constituent spins can be verified by measuring nonlocal magnetoresistance.