Coherence lengths for superconductivity in the two-orbital negative-U Hubbard model

TL;DR

This paper investigates the coherence lengths in a two-orbital negative-U Hubbard model, analyzing how interaction channels and band fillings influence superconducting coherence properties.

Contribution

It provides a detailed analysis of coherence lengths in a two-orbital negative-U Hubbard model, highlighting the effects of intra- and inter-orbital interactions.

Findings

Critical and noncritical correlation lengths depend on interaction channels.

Band fillings significantly influence coherence lengths.

Superconducting phase transition driven by intra- and inter-orbital interactions.

Abstract

We study the peculiarities of coherency in the superconductivity of two-orbital system. The superconducting phase transition is caused here by the on-site intra-orbital attractions (negative-U Hubbard model) and inter-orbital pair-transfer interaction. The dependencies of critical and noncritical correlation lengths on interaction channels and band fillings are analyzed.