Giant anomalous Hall and Nernst effect in magnetic cubic Heusler compounds

Jonathan Noky,Claudia Felser,Yan Sun,Yang Zhang,Johannes Gooth

doi:10.1038/s41524-020-0342-5

Abstract

The interplay of magnetism and topology opens up the possibility for exotic linear response effects, such as the anomalous Hall effect and the anomalous Nernst effect, which can be strongly enhanced by designing a large Berry curvature in the electronic structure. Magnetic Heusler compounds are a promising class of materials for this purpose because they are versatile, show magnetism, and their electronic structure hosts strong topological features. Here, we provide a comprehensive study of the intrinsic anomalous transport for magnetic cubic full Heusler compounds and we illustrate that several Heusler compounds outperform the best so far reported materials. The results reveal the importance of symmetries, especially mirror planes, in combination with magnetism for giant anomalous Hall and Nernst effects, which should be valid in general for linear responses (spin Hall effect, spin orbital torque, etc.) dominated by intrinsic contributions.

Highlights

In recent years a huge effort has been put in identifying topological phases of matter in real materials, culminating in a way to classify all materials via elementary band representation theory[1,2,3,4]
Apart from that the linear response is mostly influenced by the exact position of the Berry curvature (BC) in the band structure with respect to the Fermi level
For Heusler compounds, this can be linked to the number of valence electrons with two sweet spots at 21 and 28 electrons per unit cell

Summary

Introduction

In recent years a huge effort has been put in identifying topological phases of matter in real materials, culminating in a way to classify all materials via elementary band representation theory[1,2,3,4]. Apart from that the linear response is mostly influenced by the exact position of the BC in the band structure with respect to the Fermi level. AHC and/or ANC, which is close to or even exceeds the highest values that are reported so far. It is important to note, that both AHC and ANC are strongly dependent on the position of the Fermi level and on the doping of the investigated material.

Results

Conclusion