Dynamical coupling in circuit-QED

Circuit quantum electrodynamics (circuit-QED), which consists of superconducting qubits coupled to electromagnetic cavity modes, has become well known for being one of the most promising platforms for quantum information science and quantum computation. The prominent advantage being the engineered circuits and strong light-matter interaction, however this interaction is static and set by the circuit design. I will discuss an Optomechanics inspired technique, where microwave drives control the coupling of a Transmon qubit to a cavity mode, which leads to a dynamically tunable coupling operator. This technique has enabled to demonstrate the manipulation of a qubit using the Quantum Zeno Effect, the simultaneous measurement of two non-commuting observables, and also to enhance qubit readout using squeezed light. This scheme generalizes to multi-level systems, where a large family of operators may be accessed directly and simultaneously.