Scientists from the research group of Professor Johannes Fink at the Institute of Science and Technology Austria (IST Austria) along with collaborators Stefano Pirandola from the Massachusetts Institute of Technology (MIT) and the University of York, UK and David Vitali from the University of Camerino, Italy have come up with a new type of detection technology called ‘microwave quantum illumination’ that uses entangled microwave photons as a method of detection.
The prototype known as ‘quantum radar’ can detect objects in noisy thermal environments where classical radar systems often fail. The technology has potential applications for ultra-low-power biomedical imaging and security scanners.
The researchers entangle two groups of photons called the ‘signal’ and ‘idler’ photons. The ‘signal’ photons are sent out towards the object of interest and the ‘idler’ photons are measured in relative isolation, free from interference and noise. When the signal photons are reflected, true entanglement between the signal and idler photons is lost, but a small amount of correlation survives, creating a signature or pattern that describes the existence or the absence of the target object irrespective of the noise within the environment. The quantum entanglement generated at a few thousandths of a degree above absolute zero (-273.14 °C) helped in detecting low reflectivity objects at room temperature.
At low power levels, conventional radar systems typically suffer from poor sensitivity as they have trouble distinguishing the radiation reflected by the object from naturally occurring background radiation noise. Quantum illumination offers a solution to this problem as the similarities between the ‘signal’ and ‘idler’ photons generated by quantum entanglement makes it more effective to distinguish the signal photons (received from the object of interest) from the noise generated within the environment.
The research has effectively demonstrated a new method of detection that in some cases may already be superior to classical radar. According to the researchers, this scientific result was only possible by bringing together theoretical and experimental physicists that are driven by the curiosity of how quantum mechanics can help to push the fundamental limits of sense. However, a lot more has to be done to make the result applicable to real-world detection tasks and that will be possible with the help of experienced electrical engineers