ИСТИНА

We propose a control element for a Josephson spin valve. It is a complex Josephson device containing ferromagnetic (F) layer in the weak-link area consisting of two regions, representing 0 and p Josephson junctions, respectively. The valve’s state is deined by mutual orientations of the F-layer magnetization vector and boundary line between 0 and p sections of the device. We consider possible implementation of the control element by introduction of a thin normal metal layer in a part of the device area. By means of theoretical simulations, we study properties of the valve’s structure as well as its operation, revealing such advantages as simplicity of control, high characteristic frequency, and good legibility of the basic states. In addition we discuss several general properties of the current transport through a long Josephson junction with alternating critical current density. This alternating density can be achieved in experiment by incorporating of the magnetic layer to the weak link in a special way. Prospects for the practical use of such structures are related to the possibility of obtaining bistable Josephson elements on their basis. Joint analysis for both the current-phase relations and the dynamic characteristics allowed to optimize the operation mode for fast superconducting memory cell based on the bistable contact and to assess the energy dissipation for ”Read” and ”Write” operations.