2013/06/05 by Yong-Lei Wang, Michael Latimer, M. L. Latimer +9 · 2 citations
Engineering · Physics and Astronomy · #Physics of Superconductivity and Magnetism #Superconducting Materials and Applications #Superconductivity in MgB2 and Alloys #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.87.220501
published as Phys. Rev. B 87, 220501(R) (2013) · 5 pages, 3 figures
openalex publication_date 2013/06/05 · arxiv created 2013/06/06 · arxiv updated 2013/06/07 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The maximum current (critical current) a type-II superconductor can transmit without energy loss is limited by the motion of the quantized magnetic flux penetrating into a superconductor. Introducing nanoscale holes into a superconducting film has been long pursued as a promising way to increase the critical current. So far the critical current enhancement was found to be mostly limited to low magnetic fields. Here we experimentally investigate the critical currents of superconducting films with a conformal array of nanoscale holes that have nonuniform density while preserving the local ordering. We find that the conformal array of nanoscale holes provides a more significant critical current enhancement at high magnetic fields. The better performance can be attributed to its arching effect that not only gives rise to the gradient in hole density for pinning vortices with a wide range of densities but also prevents vortex channeling occurring in samples with a regular lattice of holes.