  Circuit quantum electrodynamics, consisting of superconducting artificial
atoms coupled to on-chip resonators, represents a prime candidate to implement
the scalable quantum computing architecture because of the presence of good
tunability and controllability. Furthermore, recent advances have pushed the
technology towards the ultrastrong coupling regime of light-matter interaction,
where the qubit-resonator coupling strength reaches a considerable fraction of
the resonator frequency. Here, we propose a qubit-resonator system operating in
that regime, as a quantum memory device and study the storage and retrieval of
quantum information in and from the Z2 parity-protected quantum memory, within
experimentally feasible schemes. We are also convinced that our proposal might
pave a way to realize a scalable quantum random-access memory due to its fast
storage and readout performances.
