The work is aimed at numerical analysis of superconducting current transport in Josephson heterostructures with the weak link composed of normal (N) and ferromagnetic (F) channels connected in parallel as well as ascertainment of the transport characteristics and current-phase relation with different topologies.
The current transport is considered for arbitrary thicknesses of the normal and ferromagnetic channels by means of numerical solution of non-linearized Usadel equation in the «dirty» limit. Andreev's diagrams method was developed and used for qualitative explanation of the obtained results.
If spacing L between superconducting electrodes tends to zero the superconducting current is determined by barrier transparency and area of SN and SF interfaces. With increase of L, correlation of the N- and F-channel contributions to the superconducting current transport changes in consequence of difference in coherence lengths.
Some possible topologies which are mostly friendly to thin-film fabrication process are suggested and both the superconducting current transport feature and the current-phase relation in the heterostructures are studied and discussed in detail. The topologies can be used in practical formation of both the pi-junctions, i.e. junctions with negative critical current, and the phi-junctions characterized by a non zero phase at zero current. Such junctions are in demand for logic and memory superconductor cells, and flux quantum bits (qubits).