Spin Transport through the metallic antiferromagnet FeMn

TL;DR

This study explores spin transport in metallic antiferromagnet FeMn using spin pumping and inverse spin Hall effects, revealing electronic and magnonic regimes with different distance extents and temperature dependencies.

Contribution

It introduces a method to distinguish electronic and magnonic spin transport in FeMn, demonstrating their different characteristics and temperature effects.

Findings

Magnon spin currents extend up to 9 nm in FeMn.

Spin transport regimes are distinguished as electronic and magnonic.

Magnonic spin transport is enhanced near the antiferromagnetic ordering temperature.

Abstract

We investigate spin transport through metallic antiferromagnets using measurements based on spin pumping combined with inverse spin Hall effects in Ni80Fe20/FeMn/W trilayers. The relatively large magnitude and opposite sign of spin Hall effects in W compared to FeMn enable an unambiguous detection of spin currents transmitted through the entire FeMn layer thickness. Using this approach we can detect two distinctively different spin transport regimes, which we associate with electronic and magnonic spin currents respectively. The latter can extend to relatively large distances (up to 9 nm) and is enhanced when the antiferromagnetic ordering temperature is close to the measurement temperature.