We propose schemes to create cluster states and $W$ states by many superconducting quantum-interference-device qubits in cavities under the influence of the cavity decay. Our schemes do not require auxiliary qubits, and the excited levels are only virtually coupled throughout the scheme, which could much reduce the experimental challenge. We consider the cavity decay in our model and analytically demonstrate its detrimental influence on the prepared entangled states.

• Received 5 May 2006

DOI:https://doi.org/10.1103/PhysRevA.74.024303