Magnetoelectronic Spin Echo

TL;DR

This paper predicts a magnetoelectronic spin echo phenomenon where a transverse spin current reappears after passing through a layered ferromagnetic structure, akin to nuclear spin echoes, and proposes an experimental measurement method.

Contribution

It introduces the concept of a magnetoelectronic spin echo in layered ferromagnetic-normal-ferromagnetic structures, a novel effect in spin transport physics.

Findings

Transverse spin current decays in a single ferromagnet

Adding an antiparallel ferromagnet restores the spin current

Proposed experimental setup to observe the spin echo

Abstract

We predict a spin echo in electron transport through layered ferromagnetic-normal-ferromagnetic metal structures: whereas a spin current polarized perpendicular to the magnetization direction decays when traversing a single homogeneous ferromagnet on the scale of the ferromagnetic spin-coherence length, it reappears by adding a second identical but antiparallel ferromagnet. This re-entrant transverse spin current resembles the spin-echo effect in the magnetization of nuclei under pulsed excitations. We propose an experimental setup to measure the magnetoelectronic spin echo.