Multi-vortex versus interstitial vortices scenario in superconducting antidot arrays

Abstract

In superconducting thin films, engineered lattice of antidots (holes) act as an array of columnar pinning sites for the vortices and thus lead to vortex matching phenomena at commensurate fields guided by the lattice spacing. The strength and nature of vortex pinning is determined by the geometrical characteristics of the antidot lattice (such as the lattice spacing $a_0$, antidot diameter $d$, lattice symmetry, orientation, etc) along with the characteristic length scales of the superconducting thin films, viz., the coherence length ($\xi$) and the penetration depth ($\lambda$). There are at least two competing scenarios: (i) multiple vortices sit on each of the antidots at a higher matching period, and, (ii) there is nucleation of vortices at the interstitial sites at higher matching periods. Furthermore it is also possible for the nucleated interstitial vortices to reorder under suitable conditions. We present our experimental results on NbN antidot arrays in the light of the above scenarios.

Submitted to ISS2009 proceedings; references added

References in corpus (6)

• Superconducting properties and Hall Effect of epitaxial NbN thin films
• Vortex configurations and critical parameters in superconducting thin films containing antidot arrays: Nonlinear Ginzburg-Landau theory
• Superconducting films with antidot arrays - novel behavior of the critical current
• Moving Vortex Phases, Dynamical Symmetry Breaking, and Jamming for Vortices in Honeycomb Pinning Arrays
• Vortex matching effect in engineered thin films of NbN
• Observation of Vortex Matching Phenomena in Antidot Array of NbN Thin Film