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Large Anomalous Hall Effect in a Half-Heusler Antiferromagnet

Published

Author(s)

T. Suzuki, Robin Michael Daub Chisnell, A. Devarakonda, Y.-T. Liu, W. Feng, D. Xiao, Jeffrey W. Lynn, J. G. Checkelsky

Abstract

The quantum mechanical (Berry) phase of the electronic wavefunction has profound effects on spin-dependent behavior in solids [2,2]. In the context of electronic transport, the Berry phase plays a critical role as a fundamental origin of the anomalous [3,4] and spin Hall effects [5,6], including their quantized limits [7,9]. Theoretical and experimental studies have seen significant progress in understanding these effects in ferromagnetic systems, where the separation of Berry phase and extrinsic contributions has been established [10]. Despite their apparent similarities, less is known about Berry phase effects in antiferromagnetic systems. Here we present a study of single crystals of face-centered-cubit (FCC) antiferromagnet GdPtBi that shows an anomalous Hall angle θAH>0.1 comparable to the largest anomalous Hall angles in bulk ferromagnets [11] and significantly larger than any previous report in antiferromagnetic systems [10]. Comparing the field-dependent spin structure deduced from neutron scattering with the related cases of strongly frustrated pyrochlores [12,13] and non-centrosymmetric B20 systems with Skyrmionic textures [14,15] where spin-chirality effects are important, suggests that the mechanism in the present system belongs to a more general intrinsic class originating from the combination of spin-orbit coupling and magnetic texture in non-collinear antiferromagnetic systems [16]. Furthermore, the half Heusler system to which GdPtBi belongs has been predicted to host topologically non-trivial states if distorted [17,18] or through realizing an emergent symmetry upon antiferromagnetic order [19]; the magnetic textures indicated by the measurements here imply pathways toward both of these new topological platforms.
Citation
Nature Physics
Volume
12
Issue
12

Keywords

Hall Effect, Conductivity, Berry Phase, Antiferromagnet, Neutron Diffraction, Field Dependence, Topological Insulator
Created December 1, 2016, Updated November 6, 2017