ИСТИНА

Nowadays the Josephson junctions with magnetic weak links attract special attention due to their possible applications a number of future devices, such as superconducting MRAM, logic, quantum bits and neural networks [1]. The interaction between superconducting and ferromagnetic orders in the proximized area of ferromagnetic SFS junctions provides phenomenon of 0-π oscillation of pairing amplitude in the structure. The effect permits to organize superconducting memory devices in new principals. The S-IsF-S junction with composite interlayer consists of tunnel barrier I, thin superconducting film s and ferromagnetic layer F combines high performance of the tunnel SIS junctions and special properties of magnetic SFS devices. We developed a microscopic theory of the electron transport in these devices in the frame of the Usadel equations. We have found that 0-π transition in SIsFS junction can be hidden during the measurement of critical current, due to formation of multiple branches in the current-phase relation (CPR) shape [2]. We demonstrate that the effect is the direct consequence of the significant second harmonic in CPR of the ferromagnetic sFS part of the SIsFS device. Furthermore, we find that decrease of the thickness of the intermediate s-layer leads to the significant deviation of pair potential Δ at 0 and π - phase. It modifies the critical current of tunnel SIs junction and provides possibility for macroscopic distinguish the phase shift. We also study dynamic properties of the SIsFS junction in the frame of the modified RSJ model taking into account nonequilibrium processes in s-layer [3]. We find that appearance of the voltage on tunnel layer doesn’t influence on the current properties of sFS-junction, but sFS-junction in resistive state acts as internal pumping for SIs-weak link. This work was supported in part by the Projects RFBR-18-32-00672 mol_a and 17-12-01079 from Russian Science Foundation. 1.I. I. Soloviev, N. V. Klenov, S. V. Bakurskiy, M. Yu Kupriyanov, A. L. Gudkov, and A. S. Sidorenko. Beyond Moore’s technologies: operation principles of a superconductor alternative. Beilstein Journal of Nanotechnology, 8:2689–2710, 2017. 2. S. V. Bakurskiy, V. I. Filippov, V. I. Ruzhickiy, N. V. Klenov, I. I. Soloviev, M. Yu Kupriyanov, and A. A. Golubov. Current-phase relations in SIsFS junctions in the vicinity of 0-π transition. Physical Review B -Condensed Matter and Materials Physics, 95(9):094522–1–094522–11, 2017 3. J. Keller, and D. A. Ryndyk, Phys. Rev. B 71, 054507, 2005