On the Theory of "Odd"-Pairing Superconductors

TL;DR

This paper explores a theoretical model of superconductivity with an odd energy gap function, revealing conditions for its existence, its robustness against repulsive interactions, and its sensitivity to impurities.

Contribution

It introduces an exactly solvable model for odd-parity pairing, analyzing its properties and effects of impurities, advancing understanding of unconventional superconductivity.

Findings

Odd pairing can exist despite strong repulsive interactions.

Normal impurities rapidly suppress odd pairing.

Exact solutions elucidate the interplay of even and odd pairing.

Abstract

We consider the model of superconducting pairing with the energy gap function which is odd over $k-k_{F}$.\ In this case superconductivity is possible even in the presence of an arbitrarily large point-like repulsion between electrons,\ which is attractive for the theory of high-temperature superconductors.\ We discuss mainly a model pairing interaction for which the BCS equations can be solved exactly,\ allowing the complete analysis of the interplay of the usual (``even'') and ``odd'' pairing,\ depending on the coupling constant.\ We also show that the normal impurities (disorder) lead to a rapid degradation of the ``odd'' pairing,\ which is even more rapid than in case of magnetic impurities in traditional superconductors.