When detecting signals in a CV-QKD (continuous-variable quantum key distribution) it is essential that as little as possible noise is added by the electronics. For each little bit of noise added by the amplifiers the range that the signal can be detected will drop, and the speed at which keys can be distributed plummets significantly. Of course we would like to have long-range and fast communications! This way, secure communication can reach many people.

In UNIQORN, partner imec (https://www.imec-int.com/en) develops quiet amplifiers that add very little noise and hence enable longer reaches and faster CV-QKD transmission. By using tiny semiconductor transistors, invisible to the naked eye, the signal is amplified from something which is practically invisible to oscilloscopes to something which can readily be processed. In the picture below you can see the UNIQORN ultra-low noise amplifier chip, which is only halve the size of a grain of rice (2.4mm x 2.4mm), attached to an optical chip.