Condensed Matter Seminar: "Quantum electrodynamics in 1D using a superconducting artificial atom"

We have studied the strong coupling of a single artificial atom, formed from a superconducting qubit, to an open transmission line. This produces an almost ideal 1D quantum electrodynamic system. In a series of experiments, we have already demonstrated a number of interesting physical effects. For instance, we demonstrated that the coherent scattering of microwaves from the atom leads to the strong extinction (>99%) of the transmitted light, an effect long predicted but never observed in conventional quantum optics. In the same work, we demonstrated a rudimentary single-photon router in the microwave regime. In the next experiment, we proved that the microwaves scattered from the artificial atom are definitively nonclassical. We did this by demonstrating photon antibunching in the reflected signal, using a microwave photon statistics analyzer developed in our lab. In a third experiment, we demonstrated the giant cross-Kerr effect, an effective interaction between two photons mediated by the artificial atom. There has been great interest in the cross-Kerr effect for a number of potential applications such as photonic quantum gates and quantum nondemolition measurements (QND) of photons. In more recent experiments, we have studied the interaction of the artificial atom with its own image in a superconducting "mirror." In this talk, I will review these experiments and discuss prospects for future work.