Exact Results on Superconductivity due to Interband Coupling

TL;DR

This paper introduces exactly solvable models demonstrating novel interband superconductivity, revealing properties distinct from traditional BCS superconductors through explicit Hamiltonian diagonalization and phase diagram analysis.

Contribution

It presents a new class of exactly solvable models with interband pairing, expanding understanding of superconductivity beyond BCS theory.

Findings

Discovery of novel superconducting phases with interband pairing

Explicit diagonalization of Hamiltonians using hidden $SU(2)$ algebra

Identification of properties different from BCS superconductors

Abstract

We present a family of exactly solvable models at arbitrary filling in any dimensions which exhibit novel superconductivity with interband pairing. By the use of the hidden $SU(2)$ algebra the Hamiltonians were diagonalized explicitly. The zero-temperature phase diagrams and the thermodynamic properties are discussed. Several new properties are revealed which are different from those of the BCS-type superconductor.