Spin relaxation signature of colossal magnetic anisotropy in platinum atomic chains

TL;DR

This study uses first-principles spin dynamics simulations to identify how colossal magnetic anisotropy (CMA) uniquely influences spin relaxation in platinum nanowires, showing a significant acceleration compared to uniaxial anisotropy, with potential experimental detection at low temperatures.

Contribution

It provides the first detailed analysis of the spin relaxation signature of CMA in platinum atomic chains using advanced simulations.

Findings

CMA causes a large speed-up of spin relaxation in platinum nanowires.

Distinct spin relaxation signatures can differentiate CMA from other anisotropies.

Experimental detection of CMA effects is feasible at low temperatures using x-ray free electron lasers.

Abstract

Recent experimental data demonstrate emerging magnetic order in platinum atomically thin nanowires. Furthermore, an unusual form of magnetic anisotropy -- colossal magnetic anisotropy (CMA) -- was earlier predicted to exist in atomically thin platinum nanowires. Using spin dynamics simulations based on first-principles calculations, we here explore the spin dynamics of atomically thin platinum wires to reveal the spin relaxation signature of colossal magnetic anisotropy, comparing it with other types of anisotropy such as uniaxial magnetic anisotropy (UMA). We find that the CMA alters the spin relaxation process distinctly and, most importantly, causes a large speed-up of the magnetic relaxation compared to uniaxial magnetic anisotropy. The magnetic behavior of the nanowire exhibiting CMA should be possible to identify experimentally at the nanosecond time scale for temperatures below 5 K. This time-scale is accessible in e.g., soft x-ray free electron laser experiments.