Entangled photons boost for uncrackable quantum keys

Led by Matteo Clerici at Glasgow University’s James Watt School of Engineering, the team of researchers from the UK, Japan and Germany are said to have demonstrated a new method of generating and detecting quantum-entangled photons at a wavelength of 2.1μm. Their results are published in Science Advances.

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The unique, non-classical properties of entangled photons are used in applications including quantum key distribution, which makes uncrackable communications between two parties possible.

According to Glasgow University, methods of entangling photons at shorter wavelengths of between 700 and 1550nm are well-established, but those wavelengths are vulnerable to interference from sunlight when transmitted over open air. This makes them difficult to use in applications including secure satellite-to-ground and satellite-to-satellite communications.

The Glasgow-led team’s new method of generating entangled photons further into the infrared at two micrometres wavelength could help overcome these problems for the first time.