In this work, we realize a physical system - nanoengineered singly connected Josephson junction with a periodic superparamagnetic Ni/Al multilayer - that manifests supercurrent-versus-magnetic field response typical of a dc superconducting quantum interference device (SQUID); however, unlike a SQUID, which involves a superconducting loop occupying significant space, our lumped device is more suitable for miniaturization. In addition, we show that it exhibits enhanced magnetic field sensitivity as compared with conventional superconductor-insulator-superconductor Josephson junctions. SQUID-like oscillatory response to external magnetic fields, analogous to the two-slit optical interference, is explained in terms of the dominance of Andreev bound states localized at the barrier edges in the comparatively thick and strongly anisotropic weak links. Our results may lead to significant advancement in development of nanoscale magnetic sensing techniques applicable to individual molecules or magnetic nanoparticles.
ASJC Scopus subject areas
- Physics and Astronomy(all)