Multicondensate Superconductivity in a Generalized BEC Formalism with Hole Cooper Pairs

Abstract

We sketch the generalized Bose-Einstein condensation (GBEC) formalism of a ternary boson-fermion (BF) model to study the critical transition temperature T c of a superconductor. This ternary model contrasts with the more familiar binary models of, e.g., Eagles, Ranninger et al., T.D. Lee et al., etc. The fermions are unpaired electrons (e) or, without loss of generality, holes (h); the bosons are Cooper pairs (CPs) each of both these fermions. In essence, the GBEC is a statistical model, as is the Bardeen-Cooper-Schrieffer (BCS) theory also, and yields three condensed chemically-and thermodynamically-stable phases: two pure phases, one for electron Cooper pairs (2e-CPs), and the other for hole Cooper pairs (2h-CPs), along with a mixed phase in arbitrary proportions of each of the two pure phases. The explicit inclusion of 2h-CPs dramatically increases the T c of a superconductor with respect to BCS besides including as special cases all known statistical models of superconductors.

Superstripes in the Low Energy Physics of Complex Quantum Matter at the Mesoscale

“…The physics of the unconventional superconducting phases made of multicondensates [33] has been the object of many reports [34][35][36][37] and of a school on solid state physics held in the previous week.…”