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arXiv · 0706.2674

The Lorenz number in CeCoIn$_5$ inferred from the thermal and charge Hall currents

Y. Onose·N. P. Ong·C. Petrovic
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Abstract

The thermal Hall conductivity $κ_{xy}$ and Hall conductivity $σ_{xy}$ in CeCoIn$_5$ are used to determine the Lorenz number ${\cal L}_H$ at low temperature $T$. This enables the separation of the observed thermal conductivity into its electronic and non-electronic parts. We uncover evidence for a charge-neutral, field-dependent thermal conductivity, which we identify with spin excitations. At low $T$, these excitations dominate the scattering of charge carriers. We show that suppression of the spin excitations in high fields leads to a steep enhancement of the electron mean-free-path, which leads to an interesting scaling relation between the magnetoresistance, thermal conductivity and $σ_{xy}$.

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Y. Onose, N. P. Ong, C. Petrovic. 2007-09-07. The Lorenz number in CeCoIn$_5$ inferred from the thermal and charge Hall currents. https://doi.org/10.1209/0295-5075/80/37005

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