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

Abstract

The thermal Hall conductivity ${\kappa }_{xy}$ and Hall conductivity ${\sigma }_{xy}$ in CeCoIn${}_5$ are used to determine the Lorenz number ${\mathcal{L}}_H$ 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 ${\sigma }_{xy}$.

arXiv comment6 pages, 7 figures Intro para slightly lengthened. Added 2 new ref

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Cited by in corpus (6)

• Non-Fermi liquids and the Wiedemann-Franz law
• Hall effect in heavy-fermion metals
• Thermal Hall Conductivity as a Probe of Gap Structure in Multi-band Superconductors: The Case of $\mathrm{B}{\mathrm{a}}_{1-\mathrm{x}}{\mathrm{K}}_{\mathrm{x}}\mathrm{F}{\mathrm{e}}_2\mathrm{A}{\mathrm{s}}_2$
• Apparent Violation of the Wiedemann-Franz law near a magnetic field tuned metal-antiferromagnetic quantum critical point
• Multiband thermal transport in the iron-based superconductor Ba1 xKxFe2As2
• Hybridization-Controlled Pseudogap State in the Quantum Critical Superconductor CeCoIn5