# Intrinsic Spin Decay Length in Antiferromagnetic Insulator

## TL;DR

This paper measures the intrinsic spin decay length in antiferromagnetic insulators, revealing it is significantly longer than previously thought, and highlights the impact of magnetic phase transitions on spin transport.

## Contribution

It demonstrates the intrinsic spin decay length in NiO and shows how it varies across the paramagnetic to antiferromagnetic transition, eliminating two-magnon scattering effects.

## Key findings

- Spin decay length exceeds 100 nm in the antiferromagnetic state.
- Spin decay length varies by two orders of magnitude across the magnetic transition.
- Two-magnon scattering strongly suppresses spin current at interfaces.

## Abstract

We report intrinsic spin decay length of an antiferromagnetic insulator. We found that at an antiferromagnetic/ferromagnetic interface, a spin current generated by spin pumping is strongly suppressed by two-magnon scattering. By eliminating the two-magnon contribution, we discovered that the characteristic length of spin decay in NiO changes by two-orders of magnitude through the paramagnetic to antiferromagnetic transition. The spin decay length in the antiferromagnetic state is longer than 100 nm, which is an order of magnitude longer than previously believed. These results provide a crucial piece of information for the fundamental understanding of the physics of spin transport.