Lateral Current Supply Scheme for Spin-Trigger Josephson Valves

Abstract

Current transport in an SF₁S₁F₂sIS Josephson junction, where one of the superconducting (S) electrodes is implemented as a spin valve (SF₁S₁F₂s) and I is the tunnel insulating barrier, has been studied. In such a valve, the state of the thin s layer is controlled by changing the relative orientation of the magnetization vectors of the ferromagnetic layers F₁ and F₂. The dependences of the critical current density J_c on the temperature, as well as on the thicknesses of the ferromagnetic and superconducting layers, are calculated for two experimentally relevant current supply scenarios: through the outer S electrode and through the thin s film of the spin valve. It has been shown that the current supply through the s film provides higher absolute values of J_c and preserves the sign of the first harmonic of the current–phase dependence even in the 0–π transition mode of the magnetic subsystem. The obtained results specify the applicability limits of simplified models of direct current flow and formulate practical criteria for interpreting experiments and designing planar Josephson spin valves.