Effect of hybridization on the specific heat jump in two-band superconductors

VP RAMUNNI, GM JAPIASSÚ Y A TROPER

PHYSICA C - SUPERCONDUTIVITY

Elsevier B.V.

Año: 2004 vol. 408 p. 358 - 360

0921-4534

We study the effect of a constant hybridization V0 in the specific heat jump ΔC at the superconducting critical temperature Tc, dealing with an exact analytical expression obtained from the extended BCS gap equation. Our model is suitable to discuss a superconducting material described by a hybridized two-band model, within an extended BCS approach. In this Hubbard like model, we assume that the electron–electron repulsion Ur and attractive electron–“phonon” interaction Ua, both occur at the narrow d-band. One observes that: (i) the ratio of the effective band masses in a homothetic band picture plays an important role in the jump, and (ii) the Hubbard like repulsive interaction is very small and plays no significant role in the range of temperatures where superconductivity occurs.