Superconductor-Insulator Magneto-Oscillations in Superconducting Strips

TL;DR

This paper models the magnetoresistance oscillations in thin superconducting strips near the superconductor-insulator transition, revealing quantum phase transitions of the Ising type and explaining experimental oscillatory behavior.

Contribution

It introduces a quasi-1D vortex model mapping to 1D fermions, uncovering a quantum phase transition mechanism explaining magnetoresistance oscillations.

Findings

Quantum phase transition of Ising type at critical vortex filling.

Magnetoresistance R(B) exhibits oscillations at T->0.

Model aligns with experimental observations of oscillatory magnetoresistance.

Abstract

The magnetoresistance of thin superconducting strips subject to a perpendicular magnetic field B and low temperatures T manifests a sequence of alternating superconductor-insulator transitions (SIT). We study this phenomenon within a quasi one-dimensional (1D) model for the quantum dynamics of vortices in a line-junction between coupled parallel SC wires, at parameters close to their SIT. Mapping the vortex system to 1D Fermions at a chemical potential dictated by B, we find that a quantum phase transition of the Ising type occurs at critical values of the vortex filling, from a SC phase near integer filling to an insulator near 1/2-filling. For T->0, the resulting magnetoresistance R(B) exhibits oscillations similar to the experimental observation.