Аннотация:We investigate Magnetic Josephson Junction (MJJ) - a superconducting device with ferromagnetic
barrier for a scalable high-density cryogenic memory compatible with energy-efficient single flux
quantum (SFQ) circuits. We fabricate Nb-Al/AlOx-Nb-PdFe-Nb superconductor-insulatorsuperconductor-
ferromagnet-superconductor (SIS’FS) MJJs using a co-processing approach with a
combination of HYPRES and ISSP fabrication processes. The resultant SIS’FS structure with superconductivity
of S’-layer is substantially suppressed by the adjacent ferromagnet compatible to the one
used for superconducting SFQ electronics allowing a seamless integration of MJJ-based circuits and
SIS JJ-based ultra-fast digital SFQ circuits. We report experimental results for MJJs, convincingly
proving their applicability for superconducting memory and digital circuits. By applying magnetic
field pulses, we switched between MJJ logic states “0” and “1” that are different in voltage by ~ 2
mV. These MJJs exhibit IcRn product 30% lower than that of conventional SIS junction co-produced
in the same fabrication. Additionally, we address memory retention properties of SIS’FS MJJs. Analytical
calculation and numerical simulation for these SIS’FS structures are in good agreement with
the experiment. We will discuss application of MJJ devices for memory and programmable logic circuits.
