Bidirectional Generation of Itinerant Microwave Photons with Waveguide Quantum Electrodynamics (Part 1)

The ability to distribute and communicate quantum information between distinct processing nodes is a key requirement towards realizing a fully connected network of quantum processors. Typically, this communication is either mediated by photons that propagate between the nodes, or via a bus coupler that coherently couples adjacent nodes. However, the communication fidelity of protocols involving propagating photons are often limited due to the need for lossy components such as microwave circulators that fix the directionality. Furthermore, protocols that use bus couplers between nodes can have restricted connectivity. In this work, we present our progress towards realizing a device that is capable of bidirectionally generating and capturing propagating, or itinerant, microwave photons. We do so by taking advantage of the interference between the emission of quantum emitters in a waveguide quantum electrodynamics architecture. Such a device can then be used to form the basis of a network of quantum processors with all-to-all connectivity without the need of lossy components between nodes.