On-Demand Microwave Generator of Shaped Single Photons

Single photons are expected to play a key role in tomorrow's quantum communication networks, owing to the robustness of photonic quantum states and their ability to travel long distances. This study demonstrates a generator that can give individual photons a desired ``shape'', which can increase their efficiency when used in a quantum network. Here the emission of an artificial atom (a superconducting circuit) is controlled by manipulating quantum vacuum fluctuations on nanosecond timescales. This tunable coupling principle could also see use in controlling quantum interactions in a variety of applications beyond single-photon generation.