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Free keywords:
anomalous Hall effect, Berry curvature, ionic gating, magnetism, polar structure, Antiferromagnetism, Band structure, Ferroelectric materials, Ferroelectricity, Hall effect, Anomalous hall effects, Antiferromagnets, Berry curvature, Electronic.structure, Ferromagnets, Ionic gating, Magnetoelectric materials, Polar semiconductors, Polar structures, Time reversal symmetries, Electronic structure
Abstract:
Progress in magnetoelectric materials is hindered by apparently contradictory requirements for time-reversal symmetry broken and polar ferroelectric electronic structure in common ferromagnets and antiferromagnets. Alternative routes can be provided by recent discoveries of a time-reversal symmetry breaking anomalous Hall effect (AHE) in noncollinear magnets and altermagnets, but hitherto reported bulk materials are not polar. Here, the authors report the observation of a spontaneous AHE in doped AgCrSe2, a layered polar semiconductor with an antiferromagnetic coupling between Cr spins in adjacent layers. The anomalous Hall resistivity 3 (Formula presented.) is comparable to the largest observed in compensated magnetic systems to date, and is rapidly switched off when the angle of an applied magnetic field is rotated to ≈80° from the crystalline c-axis. The ionic gating experiments show that the anomalous Hall conductivity magnitude can be enhanced by modulating the p-type carrier density. They also present theoretical results that suggest the AHE is driven by Berry curvature due to noncollinear antiferromagnetic correlations among Cr spins, which are consistent with the previously suggested magnetic ordering in AgCrSe2. The results open the possibility to study the interplay of magnetic and ferroelectric-like responses in this fascinating class of materials. © 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.
