Nucleation of superconducting pairing states at mesoscopic scales at zero temperature

TL;DR

This paper demonstrates that spin-polarized disordered Fermi liquids can develop superconducting pairing at mesoscopic scales under high magnetic fields, with a universal length scale influenced by conductance.

Contribution

It reveals the instability of polarized Fermi liquids to superconducting pairing at mesoscopic scales and characterizes the distribution and length scale dependence on conductance and magnetic field.

Findings

Superconducting pairing states can nucleate at high magnetic fields.

The distribution function depends solely on film conductance.

The pairing length scale decreases with increasing magnetic field.

Abstract

We find the spin polarized disordered Fermi liquids are unstable to the nucleation of superconducting pairing states at mesoscopic scales even when magnetic fields which polarize the spins are substantially higher than the critical one. We study the probability of finding superconducting pairing states at mesoscopic scales in this limit. We find that the distribution function depends only on the film conductance. The typical length scale at which pairing takes place is universal, and decreases when the magnetic field is increased. The number density of these states determines the strength of the random exchange interactions between mesoscopic pairing states.