Anomalous Hall effect in L10-MnAl films with controllable orbital two-channel Kondo effect

TL;DR

This paper investigates the anomalous Hall effect in L10-MnAl films, revealing how strong disorder and the orbital two-channel Kondo effect influence the Hall response, especially at low temperatures.

Contribution

It demonstrates the impact of the orbital two-channel Kondo effect on the anomalous Hall effect in disordered magnetic films, providing a new understanding of AHE behavior.

Findings

AHE scales with pAH/f=a0pxx0+bpxx2 at high temperatures.

Significant deviation from scaling occurs at low temperatures due to the orbital 2CK effect.

The deviation correlates with the breakdown temperatures and magnitude of the 2CK effect.

Abstract

The anomalous Hall effect (AHE) in strongly disordered magnetic systems has been buried in persistent confusion despite its long history. We report the AHE in perpendicularly magnetized L10-MnAl epitaxial films with variable orbital two-channel Kondo (2CK) effect arising from the strong coupling of conduction electrons and the structural disorders of two-level systems. The AHE is observed to excellently scale with pAH/f=a0pxx0+bpxx2 at high temperatures where phonon scattering prevails. In contrast, significant deviation occurs at low temperatures where the orbital 2CK effect becomes important, suggesting a negative AHE contribution. The deviation of the scaling agrees with the orbital 2CK effect in the breakdown temperatures and deviation magnitudes.