Effect of half-quantum vortices on magnetoresistance of perforated superconducting films

TL;DR

This paper investigates how half-quantum vortices influence the magnetoresistance in perforated superconducting films near the transition temperature, proposing transport measurements as a detection method based on their thermodynamic stability.

Contribution

It introduces a theoretical approach to detect half-quantum vortices through magnetoresistance measurements in perforated superconducting films.

Findings

Magnetoresistance depends on the stability of HQVs.

Application of in-plane magnetic field affects HQV stability.

Features identified may help experimental detection of HQVs.

Abstract

Recent cantilever magnetometry measurements of annular micron-size samples of Sr2RuO4 have revealed evidence for the existence of half-quantum vortices (HQVs) in this material [Jang et al. 2011]. We propose to look for HQVs in transport measurements and calculate magnetoresistance of a perforated superconducting film close to the transition temperature in the presence of HQVs. We analyze the dependence of magnetoresistance on the thermodynamic stability of HQVs which according to [Jang et al. 2011] can be varied by the application of an in-plane magnetic field and point out features which may help to identify them.