Magnetoresistance Anisotropy in Amorphous Superconducting Thin Films: A Site-Bond Percolation Approach

TL;DR

This paper models the magnetoresistance anisotropy in amorphous superconducting thin films using a site-bond percolation approach that incorporates orbital and Zeeman effects, aligning well with experimental observations.

Contribution

It introduces a generalized percolation model that accounts for both orbital and Zeeman effects to explain MR anisotropy in thin films.

Findings

Reproduces experimental MR curves with angle dependence

Shows MR dependence diminishes and changes sign at high fields

Highlights importance for understanding superconductor-insulator transition

Abstract

Recent measurements of the magnetoresistance (MR) of amorphous superconducting thin films in tilted magnetic fields have displayed several surprising experimental details, in particular a strong dependence of the MR on field angle at low magnetic fields, which diminishes and then changes sign at large fields. Using a generalized site-bond percolation model, that takes into account both the orbital and Zeeman effects of the magnetic field, we show that the resulting MR curves reproduce the main experimental features. Such measurements, accompanied by the corresponding theory, may be crucial in pinpointing the correct theory of the superconductor-insulator transition and of the MR peak in thin disordered films.