  We study a quantum computing system using microwave photons in transmission
line resonators on a superconducting chip as qubits. We show that all control
necessary for quantum computing can be implemented by coupling to Josephson
devices on the same chip, and take advantage of their strong inherent
nonlinearities to realize qubit interactions. We analyze the gate error rate to
demonstrate that our scheme is realistic even for Josephson devices with
limited decoherence times. A conceptually innovative solution based on existing
technologies, our scheme provides an integrated and scalable approach to the
next key milestone for photonic qubit quantum computing.
