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arXiv · 1210.6405

In-plane superfluid density and microwave conductivity of the organic superconductor κ-(BEDT-TTF)2Cu[N(CN)2]Br: evidence for d-wave pairing and resilient quasiparticles

S. Milbradt·A. A. Bardin·C. J. S. Truncik·W. A. Huttema·A. C. Jacko·P. L. Burn·S. -C. Lo·B. J. Powell·D. M. Broun
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Abstract

We report the in-plane microwave surface impedance of a high quality single crystal of κ-(BEDT-TTF)2Cu[N(CN)2]Br. In the superconducting state, we find three independent signatures of d-wave pairing: i) a strong, linear temperature dependence of superfluid density; ii) deep in the superconducting state the quasiparticle scattering rate Γ~ T^3; and iii) no BCS coherence peak is observed in the quasiparticle conductivity. Above T_c, the Kadowaki-Woods ratio and the temperature dependence of the in-plane conductivity show that the normal state is a Fermi liquid below ~ 23 K, yet resilient quasiparticles dominate the transport up to ~ 50 K.

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S. Milbradt, A. A. Bardin, C. J. S. Truncik, W. A. Huttema, A. C. Jacko, P. L. Burn, S. -C. Lo, B. J. Powell, D. M. Broun. 2013-08-09. In-plane superfluid density and microwave conductivity of the organic superconductor κ-(BEDT-TTF)2Cu[N(CN)2]Br: evidence for d-wave pairing and resilient quasiparticles. https://doi.org/10.1103/physrevb.88.064501

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