The ability to couple isolated quantum systems demonstrates precise and powerful control over natural phenomena. It can be of use in quantum information by connecting systems in a modular network to realize distributed, fault-tolerant quantum computing. This requires highly performing modules and efficient communication channels. Here, we describe integrated state-of-the-art hardware in circuit quantum electrodynamics intended to produce such an elementary module.
We explore the dissipation mechanisms that limit their fundamental performance and demonstrate a method to transmit quantum information from a module, via propagating photons, into another module. State transfer and entanglement are both realized with high fidelity. These results establish a compelling approach for deterministic, network-based quantum computation, and may serve as the basis for how superconducting quantum circuits can be scaled to even greater numbers.