  The generation and control of quantum states of light constitute fundamental
tasks in cavity quantum electrodynamics (QED). The superconducting realization
of cavity QED, circuit QED, enables on-chip microwave photonics, where
superconducting qubits control and measure individual photon states. A
long-standing issue in cavity QED is the coherent transfer of photons between
two or more resonators. Here, we use circuit QED to implement a three-resonator
architecture on a single chip, where the resonators are interconnected by two
superconducting phase qubits. We use this circuit to shuffle one- and
two-photon Fock states between the three resonators, and demonstrate
qubit-mediated vacuum Rabi swaps between two resonators. This illustrates the
potential for using multi-resonator circuits as photon quantum registries and
for creating multipartite entanglement between delocalized bosonic modes.
