https://doi.org/10.1140/epjb/s10051-021-00051-9
Regular Article - Solid State and Materials
Interplay of pairing correlation and Coulomb correlation in Boson exchange superconductors
1
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
Received:
5
October
2020
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
