The gap maximum of anisotropic superconductors

Abstract

For a completely general anisotropic order parameter (including changes of sign), we show that weak coupling theory is incompatible with high values of the maximum Δ_{M} of the zero temperature gap as compared to the critical temperature T_{c}, such as those found experimentally in Bi_{2}Sr_{2}CaCu_{2}O_{8+δ} where 2 Δ_{M} / T_{c} \approx 7.5 . This gives evidence for strong coupling effects. In particular this comes as a major support for a spin fluctuation mechanism with strong coupling, if one assumes that only a repulsive pairing interaction is at work in high T_{c} superconductors.

5 pages, revtex, 1 figure

References in corpus (2)

• Nodes of the superconducting gap probed by electronic Raman scattering in HgBa_{2}CaCu_{2}O_{6+δ} single crystals
• Symmetry of the superconducting gap in $HgB{a}_{2}CaC{u}_2{O}_{6+\delta }$ single crystals from electronic Raman scattering

Cited by in corpus (4)

• Specific heat of Nb_3Sn: The case for a second energy gap
• Unusual effects of anisotropy on the specific heat of ceramic and single crystal MgB2
• BCS Superconductivity in Quantum Critical Metals
• Coexistence of a triplet nodal order-parameter and a singlet order-parameter at the interfaces of ferromagnet-superconductor Co/CoO/In junctions