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تسجيل مستخدم جديدThe Lorenz number in CeCoIn$_5$ inferred from the thermal and charge Hall currents
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The thermal Hall conductivity $kappa_{xy}$ and Hall conductivity $sigma_{xy}$ 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 $sigma_{xy}$.
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The Ce compounds CeCoIn$_5$ and CeRhIn$_5$ are ideal model systems to study the competition of antiferromagnetism (AF) and superconductivity (SC). Here we discuss the pressure--temperature and magnetic field phase diagrams of both compounds. In CeRhI
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