Superconducting Pairing Amplitude and Local Density of States in Presence of Repulsive Centers

TL;DR

This paper investigates how a finite concentration of repulsive centers affects superconducting properties, revealing conditions for possible realization of $ ext{pi}$-like states and comparing with single impurity cases.

Contribution

It introduces a study of superconductors with multiple repulsive impurities using the negative U Hubbard model, extending previous single-impurity analyses.

Findings

Identification of parameter ranges for $ ext{pi}$-like states

Analysis of local density of states at impurity sites

Comparison with single impurity scenarios

Abstract

We study the properties of superconductor in presence of a finite concentration of repulsive centers. The superconductor is described by the negative $U$ Hubbard model while repulsive centers are treated as randomly distributed impurities with repulsive interaction. Analyzing the paring potential and local density of states at impurity sites we find a wide range of the system parameters where the $\pi$ - like state could possibly be realized. Comparison of our results to the single repulsive center case is also given.