Correlation between characteristic energies in non- s-wave pairing superconductors

• Published in: Physics letters. A Vol. 322; no. 5; pp. 375 - 383
• Main Authors: Angilella, G.G.N, Leys, F.E, March, N.H, Pucci, R
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 08.03.2004
• Subjects: 74.70.Tx; 74.20.-z; 74.72.-h
• ISSN: 0375-9601; 1873-2429
• DOI: 10.1016/j.physleta.2003.12.066

By solution of the Bethe–Goldstone equation for the Cooper pairing problem, an approximate analytic relation is derived between coherence length ξ and the binding energy of the Cooper pair. This relation is then qualitatively confirmed by numerically solving the corresponding self-consistent gap equations, following the crossover from weak to strong coupling, in non- s-wave superconductors. The relation applies to non-conventional superconductors, and in particular to heavy Fermions and to high- T c cuprates. Utilizing in addition a phenomenological link between k B T c and a characteristic energy ε c=ℏ 2/2m ∗ξ 2 , with m ∗ the effective mass, major differences are exposed in the functional relation between k B T c and ε c for s-wave materials and for non-conventional superconductors. The relation between critical temperature and ε c thereby proposed correctly reflects the qualitative properties of heavy Fermion superconductors.