Thermally-Activated Phase Slips in Superfluid Spin Transport in Magnetic Wires

TL;DR

This paper develops a theoretical framework for understanding thermally-activated phase slips in superfluid spin transport within magnetic wires, drawing parallels to superconducting wire theories and proposing an experimental detection method.

Contribution

It provides exact solutions for free-energy states, an analytical phase-slip rate expression, and a proposed experimental setup for observing thermal phase slips in magnetic wires.

Findings

Derived exact free-energy minima and saddle points.

Provided an analytical phase-slip rate in the zero spin-current limit.

Proposed an experimental magnetoeletric circuit to detect thermal phase slips.

Abstract

We theoretically study thermally-activated phase slips in superfluid spin transport in easy-plane magnetic wires within the stochastic Landau-Lifshitz-Gilbert phenomenology, which runs parallel to the Langer-Ambegaokar-McCumber-Halperin theory for thermal resistances in superconducting wires. To that end, we start by obtaining the exact solutions for free-energy minima and saddle points. We provide an analytical expression for the phase-slip rate in the zero spin-current limit, which involves detailed analysis of spin fluctuations at extrema of the free energy. An experimental setup of a magnetoeletric circuit is proposed, in which thermal phase slips can be inferred by measuring nonlocal magnetoresistance.