Nanoscale Domain Wall Engineered Spin-Triplet Josephson Junctions and SQUID

• DOI: 10.1021/acs.nanolett.1c00273
• Publication Date: 2021-03-17T13:22:48Z
• Authors: Ekta Bhatia; Anand Srivastava; James Devine-Ston...; Nadia A. Stelmash...; Zoe H. Barber; Jason W. A. Robinson; Kartik Senapati
• Keywords: Cooper pair; Supercurrent; Domain wall (magnetism)

Spin-singlet Cooper pairs convert to spin-triplet on passing through a magnetically noncollinear structure at superconductor(S)/ferromagnet(F) interface. In this context, the generation of triplet supercurrents intrinsic ferromagnetic domain walls, which are naturally occurring magnetic features, was proposed theoretically in past decade. However, an experimental demonstration has been lacking literature, particularly because difficulty accessing single wall, is typically buried between two domains material. By patterning nanoconstriction, we have able realize nanoscale S/F/S planar junction, where wall (pinned nanoconstriction) acts as Josephson barrier. geometry, show predicted long-range supercurrent across barrier exceeding 70 nm. Using technique, demonstrated nano-SQUID device consisting Nb/Ni/Nb junctions.