Wiedemann-Franz law and nonvanishing temperature scale across the field-tuned quantum critical point ofYbRh2Si2
| Autor: | Ramzy Daou, Makariy Tanatar, Cedomir Petrovic, Rongwei Hu, Louis Taillefer, J.-Ph. Reid |
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| Rok vydání: | 2014 |
| Předmět: |
Physics
Superconductivity Phase transition Condensed matter physics 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Electronic Optical and Magnetic Materials Magnetic field Electrical resistivity and conductivity Quantum critical point 0103 physical sciences Quasiparticle Strongly correlated material 010306 general physics 0210 nano-technology Wiedemann–Franz law |
| Zdroj: | Physical Review B. 89 |
| ISSN: | 1550-235X 1098-0121 |
| DOI: | 10.1103/physrevb.89.045130 |
| Popis: | The in-plane thermal conductivity kappa and electrical resistivity rho of the heavy-fermion metal YbRh2Si2 were measured down to 50 mK for magnetic fields H parallel and perpendicular to the tetragonal c axis, through the field-tuned quantum critical point H-c, at which antiferromagnetic order ends. The thermal and electrical resistivities, w L0T/kappa and rho, show a linear temperature dependence below 1 K, typical of the non-Fermi-liquid behavior found near antiferromagnetic quantum critical points, but this dependence does not persist down to T = 0. Below a characteristic temperature T-star similar or equal to 0.35 K, which depends weakly on H, w(T) and rho(T) both deviate downward and converge as T -> 0. We propose that T-star marks the onset of short-range magnetic correlations, persisting beyond H-c. By comparing samples of different purity, we conclude that the Wiedemann-Franz law holds in YbRh2Si2, even at H-c, implying that no fundamental breakdown of quasiparticle behavior occurs in this material. The overall phenomenology of heat and charge transport in YbRh2Si2 is similar to that observed in the heavy-fermion metal CeCoIn5, near its own field-tuned quantum critical point. |
| Databáze: | OpenAIRE |
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