Flux pinning properties of superconductors with an array of blind holes

TL;DR

This study investigates how arrays of blind holes in superconducting Pb films affect vortex dynamics and flux pinning, revealing that blind holes provide weaker pinning and trap fewer flux quanta compared to antidots.

Contribution

It introduces the use of blind holes in superconductors and compares their flux pinning properties to antidots, highlighting differences in pinning strength and flux trapping capacity.

Findings

Blind holes provide weaker flux pinning than antidots.

The linear regime for vortex lattice is smaller in blind hole arrays.

Maximum flux quanta trapped is lower in blind hole arrays.

Abstract

We performed ac-susceptibility measurements to explore the vortex dynamics and the flux pinning properties of superconducting Pb films with an array of micro-holes (antidots) and non-fully perforated holes (blind holes). A lower ac-shielding together with a smaller extension of the linear regime for the lattice of blind holes indicates that these centers provide a weaker pinning potential than antidots. Moreover, we found that the maximum number of flux quanta trapped by a pinning site, i.e. the saturation number ns, is lower for the blind hole array.