Spatial correlation of fluctuations in multi-component superconducting systems

TL;DR

This paper investigates how fluctuations in multi-component superconducting systems exhibit complex spatial correlations characterized by two distinct lengths, revealing persistent short-range correlations even near phase transitions.

Contribution

It introduces a two-band model showing that superconductivity fluctuations have two characteristic lengths, leading to more complex spatial correlation patterns than in single-band systems.

Findings

Short-range correlations persist near phase transitions.

Two characteristic lengths govern fluctuation correlations.

Multi-component systems exhibit more complex behavior than single-component ones.

Abstract

We show that spatial variation and correlation of superconductivity fluctuations in a two-band model are scaled by two characteristic lengths. This results in substantially more complicated picture compared to one-band systems. In particular, short-range correlations are always present in a two-band scenario, even near the phase transition point.