Thermal conductivity through the quantum critical point in YbRh2Si2 at very low temperature

Abstract

The thermal conductivity of YbRh2Si2 has been measured down to very low temperatures under field in the basal plane. An additional channel for heat transport appears below 30 mK, both in the antiferromagnetic and paramagnetic states, respectively below and above the critical field suppressing the magnetic order. This excludes antiferromagnetic magnons as the origin of this additional contribution to thermal conductivity. Moreover, this low temperature contribution prevails a definite conclusion on the validity or violation of the Wiedemann-Franz law at the field-induced quantum critical point. At high temperature in the paramagnetic state, the thermal conductivity is sensitive to ferromagnetic fluctuations, previously observed by NMR or neutron scattering and required for the occurrence of the sharp electronic spin resonance fracture.

11 pages + Supplementary Materials

References in corpus (6)

• Fermi-liquid instabilities at magnetic quantum phase transitions
• Quantum Criticality in Heavy Fermion Metals
• Fermi-surface collapse and dynamical scaling near a quantum critical point
• Electron spin resonance in Kondo systems
• Magnetic Polarization and Fermi Surface Instability: Case of YbRh2Si2
• Strong coupling theory of heavy fermion criticality II

Cited by in corpus (10)

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• Low-Temperature Thermal Conductivity of CeRh${}_2$As${}_2$
• Strong coupling theory of heavy fermion criticality II
• Interplay between unconventional superconductivity and heavy-fermion quantum criticality: CeCu${}_2$Si${}_2$ versus YbRh${}_2$Si${}_2$
• Dimensionless ratios: characteristics of quantum liquids and their phase transitions
• Heat diffusion in the disordered electron gas
• Fate of the Wiedemann-Franz law near quantum critical points of electron systems in solids