Persistent Current in Two Coupled Rings

We report the solution of the persistent current in two coupled rings in the presence of external magnetic fluxes. We showed that the magnetic fluxes modify the global phase of the electronic wave function for multiple connected geometry formed by the coupled rings. We obtained an exact solution for the persistent current and investigated the exact solution numerically. For two large coupled rings with equal fluxes, we found that the persistent current in the two coupled rings is in fact equal to that in a single ring. This theory explains the experimental results observed in a line of sixteen coupled rings. (Phys. Rev. Lett. 86, 3124 (2001).)