Interval identification of FMR parameters for spin reorientation transition in (Ga,Mn)As

TL;DR

This study uses interval calculations to precisely determine anisotropy fields in (Ga,Mn)As, revealing temperature-induced reorientation of magnetic easy axes near the Curie temperature.

Contribution

It introduces a novel interval calculation method for analyzing ferromagnetic resonance data, enabling comprehensive parameter estimation beyond traditional analytical approaches.

Findings

Reorientation of magnetic easy axis near Curie temperature

Precise determination of anisotropy fields using interval calculations

Effective estimation of physical parameters and their uncertainties

Abstract

In this work we report results of ferromagnetic resonance studies of a 6% 15 nm (Ga,Mn)As layer, deposited on (001)-oriented GaAs. The measurements were performed with in-plane oriented magnetic field, in the temperature range between 5K and 120K. We observe a temperature induced reorientation of the effective in-plane easy axis from [-110] to [110] direction close to the Curie temperature. The behavior of magnetization is described by anisotropy fields, H_{eff} (= 4\piM -H_{2\perp}), H_{2\parallel}, and H_{4\parallel}. In order to precisely investigate this reorientation, numerical values of anisotropy fields have been determined using powerful - but still largely unknown - interval calculations. In simulation mode this approach makes possible to find all the resonance fields for arbitrarily oriented sample, which is generally intractable analytically. In 'fitting' mode we effectively utilize full experimental information, not only those measurements performed in special, distinguished directions, to reliably estimate the values of important physical parameters as well as their uncertainties and correlations.