Qdev seminar by Bharath Kannan, Atlantic Quantum

Waveguide Quantum Electrodynamics with Superconducting Qubits

Experiments in microwave quantum optics with superconducting circuits have gained a tremendous amount of attention in the past decade, particularly in the context of quantum computation, simulation, and communication. Thus far, much of this work has focused on implementations of cavity quantum electrodynamics (CQED), where atoms are coupled to the confined photonic modes of a cavity. However, the 1D nature of photonic modes and large dipole moments of artificial atoms in superconducting circuits also enable strong coupling between atoms and propagating photons. To this end, we realize an architecture known as waveguide quantum electrodynamics (WQED), where artificial atoms are strongly coupled to the continua of modes in an open waveguide. In this seminar, I will present our recent results demonstrating the on-demand generation of directional itinerant microwave photons using a WQED architecture, and the application of such photons towards communication between quantum processing nodes. Finally, I will present our realization of the “giant atom” regime of light-matter interactions, and the novel physical effects that one may observe in it.