Inhomogeneous Superconducting States of Mesoscopic Thin-Walled Cylinders in External Magnetic Fields

TL;DR

This paper theoretically explores how mesoscopic thin-walled superconducting cylinders exhibit spatially modulated states under magnetic fields, revealing unique discontinuous behaviors and signatures of FFLO states that can be experimentally detected.

Contribution

It introduces a theoretical framework for understanding inhomogeneous superconducting states in mesoscopic cylinders, highlighting the effects of electron quantization and potential experimental signatures.

Findings

Discontinuous evolution of the order parameter with magnetic field

Non-monotonic specific heat jump behavior

Potential direct detection of FFLO modulation signatures

Abstract

We theoretically investigate the appearance of spatially modulated superconducting states in mesoscopic superconducting thin-wall cylinders in a magnetic field at low temperatures. Quantization of the electron motion around the circumference of the cylinder leads to a discontinuous evolution of the spatial modulation of the superconducting order parameter along the transition line T_c(H). We show that this discontinuity leads to the non-monotonic behavior of the specific heat jump at the onset of superconductivity as a function of temperature and field. We argue that this geometry provides an excellent opportunity to directly and unambiguously detect distinctive signatures of the Fulde-Ferrell-Larkin-Ovchinnikov modulation of the superconducting order.