Magnetization transport and quantized spin conductance

TL;DR

This paper investigates magnetization transport in insulating spin systems, revealing quantized spin conductance in antiferromagnetic chains and the influence of temperature and electric fields on the transport properties.

Contribution

It provides a theoretical analysis of magnetization transport, including quantization of spin conductance in antiferromagnetic chains and the effects of electric fields, expanding understanding of spin transport phenomena.

Findings

Spin conductance remains finite in ballistic limit due to contact resistance.

Quantized spin conductance occurs in antiferromagnetic spin-1/2 chains at T=0.

Magnetization currents can produce measurable electric fields and exhibit Hall-like phenomena.

Abstract

We analyze transport of magnetization in insulating systems described by a spin Hamiltonian. The magnetization current through a quasi one-dimensional magnetic wire of finite length suspended between two bulk magnets is determined by the spin conductance which remains finite in the ballistic limit due to contact resistance. For ferromagnetic systems, magnetization transport can be viewed as transmission of magnons and the spin conductance depends on the temperature T. For antiferromagnetic isotropic spin-1/2 chains, the spin conductance is quantized in units of order $(g \mu_B)^2/h$ at T=0. Magnetization currents produce an electric field and hence can be measured directly. For magnetization transport in electric fields phenomena analogous to the Hall effect emerge.