A quantum microwave radar that outperforms classical radar by 20%

Amazing stuff!

"... A research team recently developed a quantum radar that could significantly outperform all existing radars based on classical approaches. This new radar ... concurrently measures an entangled probe and the idler microwave photon states occurring once this probe reflects from target objects, merging with thermal noise. ...
Several past studies tried to develop quantum radars that outperformed conventional radars. This quantum advantage was eventually realized using optical systems, yet before this study it was not yet achieved using microwave radiation. ..."

From the abstract:

"A central goal of any quantum technology consists in demonstrating an advantage in their performance compared to the best possible classical implementation. A quantum radar improves the detection of a target placed in a noisy environment by exploiting quantum correlations between two modes, probe and idler. The predicted quantum enhancement is not only less sensitive to loss than most quantum metrological applications, but it is also supposed to improve with additional noise. Here we demonstrate a superconducting circuit implementing a microwave quantum radar that can provide more than 20% better performance than any possible classical radar. The scheme involves joint measurement of entangled probe and idler microwave photon states after the probe has been reflected from the target and mixed with thermal noise. By storing the idler state in a resonator, we mitigate the detrimental impact of idler loss on the quantum advantage. Measuring the quantum advantage over a wide range of parameters, we find that the purity of the initial probe-idler entangled state is the main limiting factor and needs to be considered in any practical application."

A quantum radar that outperforms classical radar by 20%

Quantum advantage in microwave quantum radar (no public access)