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Linear and nonlinear electrodynamic response of bulk CaC6 in the microwave regime

A. Andreone·G. Cifariello·E. Di Gennaro·G. Lamura·N. Emery·C. Herold·J. F. Mareche·P. Lagrange
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Abstract

The linear and nonlinear response to a microwave electromagnetic field of two c-axis oriented polycrystalline samples of the newly discovered superconductor CaC6 (Tc = 11.5 K) is studied in the superconducting state down to 2 K. The surface resistance Rs and the third order intermodulation distortion, arising from a two-tone excitation, have been measured as a function of temperature and microwave circulating power. Experiments are carried out using a dielectrically loaded copper cavity operating at 7 GHz in a "hot finger" configuration. The results confirm recent experimental findings that CaC6 behaves as a weakly-coupled, fully gapped, superconductor. The weak power dependence of Rs encourages a further investigation of this novel superconductor as a possible alternative to Nb in specific microwave applications.

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A. Andreone, G. Cifariello, E. Di Gennaro, G. Lamura, N. Emery, C. Herold, J. F. Mareche, P. Lagrange. 2006-10-18. Linear and nonlinear electrodynamic response of bulk CaC6 in the microwave regime. https://doi.org/10.1063/1.2769763

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