Proximity effects in the superconductor / heavy fermion bilayer system Nb / CeCu_6

Abstract

We have investigated the proximity effect between a superconductor (Nb) and a 'Heavy Fermion' system (CeCu_6) by measuring critical temperatures $T_c$ and parallel critical fields H_{c2}^{\parallel}(T) of Nb films with varying thickness deposited on 75 nm thick films of CeCu_6, and comparing the results with the behavior of similar films deposited on the normal metal Cu. For Nb on CeCu_6 we find a strong decrease of T_c with decreasing Nb thickness and a finite critical thickness of the order of 10 nm. Also, dimensional crossovers in H_{c2}^{\parallel}(T) are completely absent, in strong contrast with Nb/Cu. Analysis of the data by a proximity effect model based on the Takahashi-Tachiki theory shows that the data can be explained by taking into account both the high effective mass (or low electronic diffusion constant), {\it and} the large density of states at the Fermi energy which characterize the Heavy Fermion metal.

arXiv comment7 pages, 2 figure. Manuscript has been submitted to a refereed journal

References in corpus (2)

• Depairing currents in the superconductor/ferromagnet proximity system Nb/Fe
• The influence of the boundary resistivity on the proximity effect

Cited by in corpus (4)

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• Interplay between charge, magnetic and superconducting order in a Kondo lattice with an attractive Hubbard interaction