  We study a hybrid quantum computing system using nitrogen-vacancy center
ensemble (NVE) as quantum memory, current-biased Josephson junction (CBJJ)
superconducting qubit fabricated in a transmission line resonator (TLR) as
quantum computing processor and the microwave photons in TLR as quantum data
bus. The storage process is seriously treated by considering all kinds of
decoherence mechanisms. Such a hybrid quantum device can also be used to create
multi-qubit W states of NVEs through a common CBJJ. The experimental
feasibility and challenge are justified using currently available technology.
