Journal Article

Universal behaviors of magnon-mediated spin transport in disordered nonmagnetic metal-ferromagnetic insulator heterostructures

Wang, Jian, Xu, Fuming, Li, Gaoyang

2023

Overview

We numerically investigate magnon-mediated spin transport through nonmagnetic metal/ferromagnetic insulator (NM/FI) heterostructures in the presence of Anderson disorder, and discover universal behaviors of the spin conductance in both one-dimensional (1D) and 2D systems. In the localized regime, the variance of logarithmic spin conductance σ 2(ln G T ) shows a universal linear scaling with its average ⟨ln G T ⟩, independent of Fermi energy, temperature, and system size in both 1D and 2D cases. In 2D, the competition between disorder-enhanced density of states at the NM/FI interface and disorder-suppressed spin transport leads to a non-monotonic dependence of average spin conductance on the disorder strength. As a result, in the metallic regime, average spin conductance is enhanced by disorder, and a new linear scaling between spin conductance fluctuation rms( G T ) and average spin conductance G T is revealed which is universal at large system width. These universal scaling behaviors suggest that spin transport mediated by magnon in disordered 2D NM/FI systems belongs to a new universality class, different from that of charge conductance in 2D normal metal systems.

• Publisher: Higher Education Press,Springer Nature B.V
• Subject: Astronomy / Astrophysics and Cosmology / Atomic / Condensed Matter Physics / Conductance / disorder-enhanced spin conductance / Ferromagnetism / Heterostructures / Investigations / Lead / Localization / magnon-mediated spin transport / Magnons / Molecular / Optical and Plasma Physics / Particle and Nuclear Physics / Physics / Physics and Astronomy / Research Article / Scaling / universal statistical behaviors