Quantum-Enhanced Noise Radar

Quantum Illumination (QI) promises improvement in the sensitivity of target detection technologies. The approach takes advantage of strong correlations that can be created in electromagnetic beams using quantum processes, through a form of entanglement. Notably, QI has proven to be very robust to the presence of noise and loss, suggesting that it may have practical applications. We have made a proof-of-principle demonstration of a novel QI protocol: quantum-enhanced noise radar (QENR). In QENR, we use a parametric amplifier to produce a two-mode squeezed (TMS) state, which exhibits continuous-variable entanglement between signal and idler beams. This state is the input to the radar system. Compared to existing proposals for QI, our protocol does not require joint measurement of the signal and idler. This greatly enhances the practicality of the system by eliminating the need for a quantum memory to store the idler. We compare the performance of a TMS source to an ideal classical source that saturates the classical bound for correlation, finding a quantum enhancement approaching a factor of 10. One of the main challenges to making QENR practical is bringing the quantum microwaves out of the cryostat. We will discuss progress towards overcoming this challenge.