Coherent coupling between a Josephson phase qubit and an LC resonant cavity

We have taken the first step towards the implementation of cavity QED quantum information processing with Josephson phase qubits. We have observed for the first time a coherent interaction between a phase qubit and an LC cavity formed by a 7 mm long coplanar waveguide resonant at 9 GHz. At the co- resonant point of the qubit and cavity, we observe splitting of the qubit's spectral line. In a time-domain measurement, we observe coherent vacuum Rabi oscillations between the qubit and oscillator.