Phase Dynamics of a Closed 0-π Josephson Junction.

The phase dynamics of a closed 0-π junction is investigated. Such a system can be realized, for example, in a small d(x2-y2)-wave superconductor embedded in a conventional s-wave superconducting matrix. The Hamiltonian of the system is derived. We prove that the system can be mapped on a quantum two-level system when the system size is small enough. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]