Anomalous planar Hall effect in a kagome ferromagnet

Abstract

The macroscopic signature for Weyl nodes so far has been the negative longitudinal magnetoresistance arising from the chiral anomaly. However, negative longitudinal magnetoresistance is not unique to chiral anomaly and can arise due to completely different mechanisms such as current jetting or in ferromagnetic systems due to the suppression of scattering with magnons. Therefore, a macroscopic effect that can be uniquely attributed to the presence of Weyl nodes is desirable. Here we show that the planar Hall effect could be a hallmark for Weyl nodes. We investigated the anisotropic magnetoresistance and planar Hall effect in Fe${}_3$Sn${}_2$, which has a kagome lattice and has been predicted to be a type II Weyl metal. We discover that the planar Hall effect contains a field antisymmetric contribution in addition to the ordinary field symmetric contribution. The field antisymmetric planar Hall effect has a 3-fold rotational symmetry, distinctively different from the symmetric planar Hall effect, but consistent with the 3-fold rotational degeneracy of the magnetization in Fe${}_3$Sn${}_2$. The temperature and field dependence of the antisymmetric planar Hall effect rules out an interpretation based on contribution from the anomalous Hall effect and is different from the symmetric planar Hall effect, pointing to a different origin. We attribute the antisymmetric planar Hall effect to the topological nature of Fe${}_3$Sn${}_2$ due to the presence of Weyl II nodes. Our finding offers a promising route for macroscopically probing Weyl systems.

arXiv comment18 pages

References in corpus (15)

• Experimental Observation of Quantum Hall Effect and Berry's Phase in Graphene
• $Z_2$ Topological Order and the Quantum Spin Hall Effect
• Anomalous Hall effect
• Quantum Spin Hall Effect
• Chiral Anomaly and Classical Negative Magnetoresistance of Weyl Metals
• Giant Planar Hall Effect in Epitaxial (Ga,Mn)As Devices
• Topological Nature of Anomalous Hall Effect in Ferromagnet
• Chiral anomaly as origin of planar Hall effect in Weyl semimetals
• Giant Planar Hall Effect in Topological Metals
• Planar Hall effect in the Weyl semimetal GdPtBi
• On the search for the chiral anomaly in Weyl semimetals: The negative longitudinal magnetoresistance
• Giant anisotropic magnetoresistance and planar Hall effect in the Dirac semimetal Cd3As2
• Magnetotransport as diagnostic of spin reorientation: kagome ferromagnet as a case study
• Field-dependent anisotropic magnetoresistance and planar Hall effect in epitaxial magnetite thin films
• Planar Hall-effect, Anomalous planar Hall-effect, and Magnetic Field-Induced Phase Transitions in TaAs

Cited by in corpus (1)

• Tuning the electronic band structure in a kagome ferromagnetic metal via magnetization