Flux effect in superconducting hybrid Aharonov-Bohm rings

We have extended the circuit theory of Andreev conductance <article>[Phys. Rev. Lett. 73, 1420 (1994)]</article> to diffusive superconducting hybrid structures that contain an Aharonov-Bohm ring. The electrostatic potential distribution in the system is predicted to be flux dependent with a period of the superconducting flux quantum Φ₀=h/2e. When at least one tunnel barrier is present, the conductance of the system oscillates with the same period.