ИСТИНА

Development of the effective superconducting memory is one of the most important challenges in the superconducting electronics. The main criteria of this challenge are scalability and performance of “write” and “read” operations of the device. Scalability of SFQ-logic cells is restricted, since they need sufficient inductance to trap the flux quantum. Magnetic memory devices on spin-valve effect are scalable; however, they require the additional circuits to control the magnetization of the layers. In addition, their performance is restricted by the remagnitization times, which are in the order of nanoseconds. Possible solution is a usage of superconducting phase memory devices based on magnetic Josephson junctions. This type of devices operates directly with the superconducting phase, which provides two distinct ground states [1] and don’t require the remagnitization of the magnetic layers. In this work, we propose some fundamental mechanisms of operation of such devices. Formation of the superconducting phase domains in the thin superconducting film of the S-F/N-s-I-S structures permits to operate logical states with Josephson currents [2]. Operation with the SIsFS junction near the 0-pi transition provides realization of the phase states, protected from elimination during the reading process [3]. The current phase relation of the SIsFS junction in this regime contains a few independent branches with a possibility of switching between them by injection of the SFQ pulse. We model the behavior of these devices in the frame of the microscopic theory of superconductivity and compare their operational properties with the main competitors from other classes of devices. [1] E. Goldobin, H Sickinger, M Weides, N Ruppelt, H Kohlstedt, R Kleiner, D Koelle, Appl. Phys. Lett. 102 (24), 242602 (2013). [2] S.V. Bakurskiy, N.V. Klenov, I.I. Soloviev, M.Yu Kupriyanov, and A.A. Golubov. Appl. Phys. Lett. ,108 ,042602 (2016). [3] S. V. Bakurskiy, V.I. Filippov, V.I. Ruzhickiy, N.V. Klenov, I. I. Soloviev, M.Yu. Kupriyanov, A.A. Golubov, arXiv:1703.04116: , accepted in Phys. Rev. B (2017). This work was supported in part by the Project No. 15-12-30030 from Russian Science Foundation, Ministry of Education and Science of the Russian Federation in the framework of Increase Competitiveness Program of NUST "MISiS" (research project K2-2016-051) and grant number MK-5813.2016.2 and by RFBR grants 17-52 560003Iran-a and 16-29-09515-ofi-m.