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

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.