## Theoretical Model of Superconducting Spintronic SIsFS Devices    [PDF]

S. V. Bakurskiy, N. V. Klenov, I. I. Soloviev, V. V. Bol'ginov, V. V. Ryazanov, I. V. Vernik, O. A. Mukhanov, M. Yu. Kupriyanov, A. A. Golubov
Motivated by recent progress in development of cryogenic memory compatible with single flux quantum (SFQ) circuits we have performed a theoretical study of magnetic SIsFS Josephson junctions, where 'S' is a bulk superconductor, 's' is a thin superconducting film, 'F' is a metallic ferromagnet and 'I' is an insulator. We calculate the Josephson current as a function of s and F layers thickness, temperature and exchange energy of F film. We outline several modes of operation of these junctions and demonstrate their unique ability to have large product of a critical current $I_{C}$ and a normal-state resistance $R_{N}$ in the $\pi$ state, comparable to that in SIS tunnel junctions commonly used in SFQ circuits. We develop a model describing switching of the Josephson critical current in these devices by external magnetic field. The results are in good agreement with the experimental data for Nb-Al/AlO${_x}$-Nb-Pd$_{0.99}$Fe$_{0.01}$-Nb junctions.
View original: http://arxiv.org/abs/1305.0836