Quantum radar is based on which technology


In principle, the way the system works is relatively simple: Instead of using conventional microwaves, the researchers entangle two groups of photons, which are referred to as “signal” and “idler”. The signal photons are emitted in the direction of the object to be detected, while the idler photons are measured relatively isolated and free from interference and noise. If the signal is reflected back, the entanglement between signal and idler photons is largely lost, only a few correlations remain. However, when the two signals are recombined, these generate a signature or a pattern that describes the existence or absence of the target object - regardless of the noise in the environment

“What we have shown is the practical proof of a theoretical concept for microwave quantum radar,” says Shabir Barzanjeh, whose research to date has contributed to developing the theoretical framework for quantum-based radar technology. “With the help of quantum entanglement, which was generated at a few thousandths of a degree above absolute zero, we were able to detect objects with very low reflectivity at room temperature.” Although the entanglement of quantum particles is in principle very unstable, the newly developed device has some fundamental advantages over conventional radars . For example, classic radar systems typically have a low sensitivity with very low signal powers, since they have difficulty distinguishing the radiation reflected from the object from naturally occurring background radiation noise. This problem can be circumvented with quantum illumination, as the similarities between the signal and idler photons make it easier to distinguish between the signal photons and the ambient noise.

“The central message of our research is that quantum radars and microwave quantum illumination do not only exist in theory, but are also possible in practice. Compared to classic coherent detectors, under the same conditions and with very low signal strengths, we see that quantum-enhanced detection can be superior, ”says Barzanjeh. The latest research results are only valid as practical proof of a theoretical concept, but Barzanjeh and colleagues were able to demonstrate a new detection method that in some cases can be superior to classic radar. "We are excited to see the effects of our research, especially for short-range microwave sensors," said Barzanjeh. Johannes Fink adds: “This scientific result was only possible through the close cooperation of theoretical and experimental physicists who are curious how quantum mechanics can be used to break through classic barriers in sensor technology. In order to benefit from our research, we also need the support of experienced electrical engineers because there is still a lot to do before the concept can be applied in practice. "

IST Austria / JOL

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