Physicists at the Institute of Science and Technology Austria (IST Austria) have invented a new radar prototype that uses quantum entanglement as a method of object detection.
This successful integration of quantum mechanics into devices could significantly impact the biomedical and security industries. The research is published in the journal Science Advances.
Quantum entanglement – a strange but potentially hugely useful quantum phenomenon where two particles are inextricably linked across space and time – could play a major role in future radar technology.
In 2008, an engineer from MIT devised a way to use the features of entanglement to illuminate objects while barely using any photons.
In certain scenarios, such technology promises to outperform conventional radar, according to its makers, particularly in noisy thermal environments.
Now, 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 demonstrated a new type of detection technology called microwave quantum illumination that utilizes entangled microwave photons as a method of detection.
The working principles behind the device are simple: Instead of using conventional microwaves,
- the researchers entangle two groups of photons, which are called the signal and idler photons.
- The signal photons are sent out towards the object of interest, whilst the idler photons are measured in relative isolation, free from interference and noise.
- When the signal photons are reflected back, 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.
“What we have demonstrated is a proof of concept for microwave quantum radar,” says quantum physicist Shabir Barzanjeh, who conducted the work at the Institute of Science and Technology Austria.
“Using entanglement generated at a few thousandths of a degree above absolute zero, we have been able to detect low reflectivity objects at room temperature.”
“The main message behind our research is that quantum radar or quantum microwave illumination is not only possible in theory but also in practice,” says Barzanjeh.
“When benchmarked against classical low-power detectors in the same conditions we already see, at very low-signal photon numbers, that quantum-enhanced detection can be superior.”
There’s plenty of exciting potential here, though we shouldn’t get ahead of ourselves just yet. Quantum entanglement remains an incredibly delicate process to manage, and entangling the photons initially requires a very precise and ultra-cold environment.