de Haas-van Alphen effect of correlated Dirac states in kagome metal Fe3Sn2

TL;DR

This study investigates the electronic structure of the kagome metal Fe3Sn2, revealing how ferromagnetic order influences topologically non-trivial Dirac states and suggesting potential for spintronic applications.

Contribution

It provides the first de Haas-van Alphen measurements of correlated Dirac states in Fe3Sn2, demonstrating magnetic control over topological electronic properties.

Findings

Massive Dirac states are confirmed via quantum oscillations.

Fermi surface areas and effective masses are modulated by magnetic moment orientation.

Berry curvature effects are linked to magnetic moment rotation.

Abstract

The field of topological electronic materials has seen rapid growth in recent years, in particular with the increasing number of weakly interacting systems predicted and observed to host topologically non-trivial bands. Given the broad appearance of topology in such systems, it is expected that correlated electronic systems should also be capable of hosting topologically non-trivial states. Interest in correlated platforms is heightened by the prospect that collective behavior therein may give rise to new types of topological states and phenomena not possible in non-interacting systems. However, to date only a limited number of correlated topological materials have been definitively reported due to both the challenge in calculation of their electronic properties and the experimental complexity of correlation effects imposed on the topological aspects of their electronic structure. Here, we report a de Haas-van Alphen (dHvA) study of the recently discovered kagome metal Fe$_3$Sn$_2$ mapping the massive Dirac states strongly coupled to the intrinsic ferromagnetic order. We observe a pair of quasi-two-dimensional Fermi surfaces arising from the massive Dirac states previously detected by spectroscopic probes and show that these band areas and effective masses are systematically modulated by the rotation of the ferromagnetic moment. Combined with measurements of Berry curvature induced Hall conductivity, we find that along with the Dirac fermion mass, velocity, and energy are suppressed with rotation of the moment towards the kagome plane. These observations demonstrate that strong coupling of magnetic order to electronic structure similar to that observed in elemental ferromagnets can be extended to topologically non-trivial electronic systems, suggesting pathways for connecting topological states to robust spintronic technologies.