Exploiting the intrinsic nonlinearity of superconducting Josephson junctions, we propose a scalable circuit with superconducting qubits (SCQs) which is very similar to the successful one now being used for trapped ions. The SCQs are coupled to the “vibrational” mode provided by a superconducting $LC$ circuit or its equivalent (e.g., a superconducting quantum interference device). Both single-qubit rotations and qubit-$LC$-circuit couplings and/or decouplings can be controlled by the frequencies of the time-dependent magnetic fluxes. The circuit is scalable since the qubit-qubit interactions, mediated by the $LC$ circuit, can be selectively performed, and the information transfer can be realized in a controllable way.

• Received 15 October 2005

DOI:https://doi.org/10.1103/PhysRevB.76.144518