Аннотация:We discuss the current status of theoretical understanding and experimental realizations of superconducting spin valves.
The interest to this problem is motivated by the recent developments, which clearly demonstrated that the achieved background in this field provides the opportunity for finding solutions for elaboration of superconducting memory cells, which can be integrated with RSFQ logic circuits. These cells are based on heterostructures, which consist of superconducting (S) materials, insulator (I), ferromagnetic (F) and normal (N) metals. Fabrication and study of such heterostructures is one of the components of the new U.S. program, providing for the next 4 years the establishment of production for the manufacture of working model of a prototype superconducting computer [1].
We start with the brief discussion of peculiarities of proximity effect in SF and SFF multilayers and their manifestation in spin valve devices controlling critical temperature of S film or conductance of one of the F layers.
The recent status of experimental and theoretical achievements in developing SIsFS and SFFS Josephson devices, which are considered as the control unit of superconducting memory cell will be discussed. Special attention will be given to the effect of formation of domain walls and normal phase inclusions in the F films on the junction critical current.
Support by RFBR grants 14-02-90018, 14-02-31002_mol_a, Ministry of Education and Science of the Russian Federation, President grant MK-1841.2014.2, and BFBR grant F14R-020 is acknowledged.
[1] D. S. Holmes, A.L.Ripple, and M.A. Manheimer, IEEE Trans. on Appl. Supercond., 23 (2013) 1701610.
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