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Dissipationless Anomalous Hall Current in the Ferromagnetic Spinel CuCr$_2$Se$_{4-x}$Br$_x$

Wei-Li Lee·Satoshi Watauchi·V. L. Miller·R. J. Cava·N. P. Ong
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Abstract

In a ferromagnet, an applied electric field $\bf E$ invariably produces an anomalous Hall current ${\bf J}_H$ that flows perpendicular to the plane defined by $\bf E$ and $\bf M$ (the magnetization). For decades, the question whether ${\bf J}_H$ is dissipationless (independent of the scattering rate), has been keenly debated without experimental resolution. In the ferromagnetic spinel CuCr$_2$Se$_{4-x}$Br$_x$, the resistivity $ρ$ (at low temperature) may be increased 1000 fold by varying $x$(Br), without degrading the $\bf M$. We show that ${\bf J}_H/E$ (normalized per carrier, at 5 K) remains unchanged throughout. In addition to resolving the controversy experimentally, our finding has strong bearing on the generation and study of spin-Hall currents in bulk samples.

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Wei-Li Lee, Satoshi Watauchi, V. L. Miller, R. J. Cava, N. P. Ong. 2004-05-25. Dissipationless Anomalous Hall Current in the Ferromagnetic Spinel CuCr$_2$Se$_{4-x}$Br$_x$. https://doi.org/10.1126/science.1094383

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