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arXiv · 0705.1052

Strong-coupling properties of unbalanced Eliashberg superconductors

E. Cappelluti·G. A. Ummarino
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Abstract

In this paper we investigate the thermodynamical properties of ``unbalanced'' superconductors, namely, systems where the electron-boson coupling $λ$ is different in the self-energy and in the Cooper channels. This situation is encountered in a variety of situation, as for instance in d-wave superconductors. Quite interesting is the case where the pairing in the self-energy is smaller than the one in the gap equation. In this case we predict a finite critical value $λ_c$ where the superconducting critical temperature $T_c$ diverges but the zero temperature gap is still finite. The specific heat, magnetic critical field and the penetration depth are also evaluated.

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E. Cappelluti, G. A. Ummarino. 2007-05-08. Strong-coupling properties of unbalanced Eliashberg superconductors. https://doi.org/10.1103/physrevb.76.104522

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