Enhancements of the superconducting transition temperature within the two-band model

TL;DR

This paper explores extensions of the two-band superconducting model, demonstrating that coupled order parameters and strong electron-lattice interactions can significantly increase the superconducting transition temperature.

Contribution

It introduces extended two-band models incorporating coupled order parameters and electron-lattice interactions, showing their impact on raising Tc.

Findings

Coupled order parameters enhance Tc.

Strong electron-lattice coupling increases transition temperature.

Substantial Tc enhancements achieved through model extensions.

Abstract

The two-band model as introduced by Suhl, Matthias and Walker [Phys. Rev. Lett. 3, 551 (1959)] accounts for multiple energy bands in the vicinity of the Fermi energy which could contribute to electron pairing in superconducting systems. Here, extensions of this model are investigated wherein the effects of coupled superconducting order parameters with different symmetries and the presence of strong electron-lattice coupling on the superconducting transition temperature Tc are studied. Substantial enhancements of Tc are obtained from both effects.