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Title: Enhancing superconducting critical current by randomness

The key ingredient of high critical currents in a type-II superconductor is defect sites that pin vortices. Here, we demonstrate that a random pinscape, an overlooked pinning system in nanopatterned superconductors, can lead to a substantially larger critical current enhancement at high magnetic fields than an ordered array of vortex pin sites. We reveal that the better performance of a random pinscape is due to the variation of the local density of its pinning sites, which mitigates the motion of vortices. This is confirmed by achieving even higher enhancement of the critical current through a conformally mapped random pinscape, where the distribution of the local density of pinning sites is further enlarged. Our findings highlight the potential of random pinscapes in enhancing the superconducting critical currents of applied superconductors in which random pin sites of nanoscale defects emerging in the materials synthesis process or through ex-situ irradiation are the only practical choice for large-scale production. Our results may also stimulate research on effects of a random pinscape in other complementary systems such as colloidal crystals, Bose-Einstein condensates, and Luttinger liquids.
Authors:
 [1] ;  [2] ;  [2] ;  [3] ;  [3] ;  [4] ;  [4] ;  [5] ;  [3]
  1. Argonne National Lab. (ANL), Argonne, IL (United States). Materials Science Division; Univ. of Notre Dame, IN (United States). Dept. of Physics
  2. Argonne National Lab. (ANL), Argonne, IL (United States). Materials Science Division; Northern Illinois Univ., DeKalb, IL (United States). Dept. of Physics
  3. Argonne National Lab. (ANL), Argonne, IL (United States). Materials Science Division
  4. Argonne National Lab. (ANL), Argonne, IL (United States). Center for Nanoscale Materials
  5. Argonne National Lab. (ANL), Argonne, IL (United States). Materials Science Division; Univ. of Illinois, Champaign, IL (United States). Dept. of Physics, Electrical and Mechanical Engineering
Publication Date:
OSTI Identifier:
1248955
Grant/Contract Number:
AC02-06CH11357; DMR-1407175
Type:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 93; Journal Issue: 4; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Science Foundation (NSF)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Superconductivity; nanopatterned; vortex