ИСТИНА

Superconductivity (S) and ferromagnetism (F), two deeply antagonistic electronic properties, can coexist in form of Josephson SFS junctions (SFS JJ). The most impressive feature of the SFS JJ is the ability to be in a Josephson state with the phase difference inversion or -state [1,2]. This feature makes the SFS JJs valuable phaseshifting elements for utilization in superconducting circuits. Recently, a Toggle Flip-Flop (TFF) with the embedded SFS -junction was successfully demonstrated [3]. The SFS JJs are also suitable for integration with Josephson qubits. A quantum Josephson circuits, a -biased qubits, has been recently demonstrated too [3,4]. Another application is based on the simplest feature of a SFS JJ that its critical current can be changed significantly by remagnetization of the F-interlayer. A Josephson magnetic memory element proposed in Ref. [5,6] requires ferromagnet layer with an in-plane magnetic anisotropy and small coercive field. Modern fundamental and applied researches make the actual implementation and study of planar multiterminal S/F/N structures. Planar Josephson S- (F/N)-S structures with complex bilayered (F/N) barriers were proposed recently in [7] and realized in [8]. The structure, which we studied in [8], included a Cu/Fe bilayer forming a bridge between two superconducting Al electrodes. 1. V.V. Ryazanov, V.A. Oboznov, A.Yu. Rusanov, A.V. Veretennikov, A.A. Golubov, and J. Aarts, Phys. Rev. Lett 86, 2427 (2001). 2. V. A. Oboznov, V.V. Bol'ginov, A. K. Feofanov, V. V. Ryazanov and A.I. Buzdin, Phys. Rev. Lett. 96, 197003 (2006). 3. A.K. Feofanov, V.A. Oboznov, V.V. Bol’ginov, J. Lisenfeld, S. Poletto, V.V. Ryazanov, A.N. Rossolenko, M. Khabipov, D. Balashov, A.B. Zorin, P.N. Dmitriev, V.P. Koshelets and A. V. Ustinov. Nature Physics 6, 593 (2010). 4. A.V. Shcherbakova, K.G. Fedorov, K.V. Shulga, V.V. Ryazanov, V.V. Bolginov, V.A. Oboznov, S.V. Egorov, V.O. Shkolnikov, M.J. Wolf, D. Beckmann, A.V. Ustinov. Superconductor Science and Technology, 28, 025009 (2015). 5. V.V. Bol’ginov, V.S. Stolyarov, D.S. Sobanin, A.L. Karpovich, and V.V. Ryazanov, JETP Letters 95, 366 (2012). 6. T. I. Larkin, V. V. Bol’ginov, V. S. Stolyarov, V. V. Ryazanov, I. V. Vernik, S. K. Tolpygo, O. A. Mukhanov, Appl. Phys. Lett. 100, 222601 (2012). 7. T. Yu. Karminskaya, A. A. Golubov, M. Yu. Kupriyanov, and A. S. Sidorenko, Phys. Rev. B 81, 214518 (2010). 8. T. E. Golikova, F. Hübler, D. Beckmann, I. E. Batov, T. Yu. Karminskaya, M. Yu. Kupriyanov, A. A. Golubov, and V. V. Ryazanov. Phys. Rev. B 86, 064416 (2012).