Quasiparticle conductivity in the heavy-fermion superconductor CeCoIn_5
Abstract
We present surface impedance measurements on the recently discovered heavy fermion superconductor CeCoIn_5, made on high-quality platelet single crystals using bolometric and resonator pertubation techniques in the frequency range 1 to 75 GHz. The layered structure of CeCoIn_5, and its relatively high transistion temperature of 2.3 K, some twenty times higher than that of its 3D parent compound CeIn_3, suggest that reduced dimensionality plays an important role in the superconductivity and have led to parallels being drawn between this material and the cuprate superconductors. Our measurements reveal another surprising similarity to the cuprates: a sharp collapse in quasiparticle scattering on entering the superconducting state. This is seen clearly in the microwave conductivity, as a rapid narrowing of the conductivity spectrum, whose width easily falls within the frequency range of our measurements due to the heavily renormalised mass of the electronic quasiparticles. This observation suggests that substantial inelastic scattering is present in the normal state, at all temperatures, and that this scattering is due to fluctuations of electronic origin.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2001
- Bibcode:
- 2001APS..MARE16002B