Magnetic Exchange-Coupled Superconducting Devices with Broken Symmetry for Cryogenic Memory

Ultrathin superconducting (SC) films embedded between two ferromagnetic insulators (FI) experience magnetic-exchange coupling, enabling the switching of the superconducting state by controlling the relative FI magnetization alignment. We investigate micrometer-scale devices patterned from such thin-film heterostructures and demonstrate their reproducible operation as nonreciprocal superconducting memory elements. Single-cell writing is realized using current-pulse-induced, heat-assisted magnetic switching. Furthermore, at a lower temperature, symmetry breaking gives the memory elements a marked nonreciprocity, with zero magnetic field superconducting diode efficiencies exceeding ±60%. These results present highly scalable FI/SC/FI hybrid structures as a contender for state-of-the art robust superconducting memories for neuromorphic superconducting computing and new data guiding schemes.