Regular Article - Solid State and Materials
Interplay of pairing correlation and Coulomb correlation in Boson exchange superconductors
Department of Condensed Matter Physics and Material Sciences, S.N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, 700106, Kolkata, India
2 Department of Physics, Ramakrishna Mission Vivekananda Educational and Research Institute, 711202, Belur, India
Accepted: 11 January 2021
Published online: 8 February 2021
A theoretical methodology for exploring the conventional Bardeen–Cooper–Schrieffer (BCS) pairing instability for superconductivity from a correlated normal phase for all possible degrees of many-body correlation has been developed. The Gutzwiller projection scheme with a correlation parameter was made use of in generating the BCS pairing state. A variational scheme was thereafter implemented, leading to a self-consistent equation for superconducting gap function. This equation shows explicit dependence of the gap function on the many body correlation parameter. This ‘pairing-gap’ and the corresponding self-consistent gap equation in zero correlation limit, becomes identical in nature with those of the pure (1-well) BCS formalism, as expected and the Coulomb correlation affects the pairing significantly with the strength of correlation. The detailed consequences are being presented here.
© The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature 2021