Enhancing the critical current in quasiperiodic pinning arrays below and above the matching magnetic flux

Abstract

Quasiperiodic pinning arrays, as recently demonstrated theoretically and experimentally using a fivefold Penrose tiling, can lead to a significant enhancement of the critical current Ic as compared to "traditional" regular pinning arrays. However, while regular arrays showed only a sharp peak in Ic (Φ) at the matching flux Φ1 and quasiperiodic arrays provided a much broader maximum at Φ< Φ1, both types of pinning arrays turned out to be inefficient for fluxes larger than Φ1. We demonstrate theoretically and experimentally the enhancement of Ic (Φ) for Φ> Φ1 by using non-Penrose quasiperiodic pinning arrays. This result is based on a qualitatively different mechanism of flux pinning by quasiperiodic pinning arrays and could be potentially useful for applications in superconducting microelectronic devices operating in a broad range of magnetic fields. © 2010 The American Physical Society.