Quantum sensing and quantum radars

Ivan B. Djordjević

David Luong, Bhashyam Balaji, Sreeraman Rajan

We discuss the feasibility of using microwave quantum radars in biomedical sensing applications, with a heavy focus on the equipment needed to operate such radars. A recent microwave quantum radar experiment used a device called a Josephson parametric amplifier (JPA) to generate quantum entangled signals. Since JPAs or JPA-like devices are expected to be used in most quantum radar implementations in the foreseeable future, we examine the operating requirements of JPAs. We find that the most important requirement for operating a JPA is the need for cryogenic cooling. This is easily accommodated in medical environments such as hospitals, so it is natural to consider whether quantum radars could work for biomedical sensing. We then find that, in fact, many of the strengths of quantum radars are naturally suited to medical contexts. We therefore conclude that the case for using JPA-based quantum radars for medical sensing is a strong one.

Abdulmohsen A. Alsaui, Octavia A. Dobre, Neel Kanth Kundu +2 more

Integrated sensing and communication (ISAC) is emerging as a key enabler for spectrum-efficient and hardware-converged wireless networks. However, classical radar systems within ISAC architectures face fundamental limitations under low signal power and high-noise conditions. This paper proposes a novel framework that embeds quantum illumination radar into a base station to simultaneously support full-duplex classical communication and quantum-enhanced target detection. The resulting integrated quantum sensing and classical communication (IQSCC) system is optimized via a sum-rate maximization formulation subject to radar sensing constraints. The non-convex joint optimization of transmit power and beamforming vectors is tackled using the successive convex approximation technique. Furthermore, we derive performance bounds for classical and quantum radar protocols under the statistical detection theory, highlighting the quantum advantage in low signal-to-interference-plus-noise ratio regimes. Simulation results demonstrate that the proposed IQSCC system achieves a higher communication throughput than the conventional ISAC baseline while satisfying the sensing requirement.

Marco O. Lanzagorta

OctoMiao

Michael Würth, Florian Bischeltsrieder, Julind Xhani +1 more

Quantum radar is a remote sensing technique for target detection at microwave frequencies that relies on photon counting measurements. In this work, we consider the problem of photon counters with only a finite photon number resolution. We identify parallels to Gaussian Boson Sampling (GBS) and use recent findings in this field to analyze quantum radar receivers. We thus demonstrate that GBS is a suitable tool to analyze quantum sensing applications. Furthermore, our results show a principal advantage of correlated photon counting at the receiver.