Circuit quantum electrodynamics with a scanning qubit

We report measurements of the coupling between a superconducting microwave resonator and a transmon qubit fabricated on a separate chip and mounted to a three-dimensional cryogenic translation stage. The qubit-resonator system reached the strong coupling regime with a coupling strength in excess of 80 MHz. We use the translation stage to explore the position dependence of the coupling strength. With a scanning qubit stage, it is possible to measure many qubits in succession and study the statistics of the fabrication process. The system can also be used as a local probe of a large array of microwave cavities and superconducting qubits.