Thermal rounding of the depinning transition in ultrathin Pt/Co/Pt films

TL;DR

This study investigates the thermal rounding of the depinning transition in ultrathin Pt/Co/Pt films, confirming universal scaling behavior and exponents consistent with theoretical models of elastic interfaces.

Contribution

The paper provides experimental validation of the universal depinning exponents for magnetic domain walls in ultrathin films, aligning with theoretical predictions for the quenched Edwards-Wilkinson model.

Findings

Scaling behavior matches theoretical exponents

Depinning exponent β ≈ 0.33 confirmed

Thermal rounding exponent ψ ≈ 0.2 confirmed

Abstract

We perform a scaling analysis of the mean velocity of extended magnetic domain walls driven in ultrathin Pt/Co/Pt ferromagnetic films with perpendicular anisotropy, as a function of the applied external field for different film-thicknesses. We find that the scaling of the experimental data around the thermally rounded depinning transition is consistent with the universal depinning exponents theoretically expected for elastic interfaces described by the one-dimensional quenched Edwards-Wilkinson equation. In particular, values for the depinning exponent $\beta$ and thermal rounding exponent $\psi$ are tested and the present analysis of the experimental data is compatible with $\beta=0.33$ and $\psi=0.2$, in agreement with numerical simulations.