Quantum computers promise to solve computational problems that will always be impractical for classical computers, but today’s prototypes must still be scaled up for practical applications. Photonic quantum computers have shown great potential for scalability but several bottlenecks hinder such a scaling. In particular, reading out the individual photons after quantum processing asks for very large arrays of extremely sensitive single-photon detectors, which do not exist yet.
A scalable cryogenic electronic interface for large-scale photon detectors
Superconducting Nanowire Single Photon Detectors (SNSPDs) are routinely used in photonic quantum computers. However, existing SNSPD systems are limited to a maximum of 48 channels, while tens of thousands of channels are needed. Since SNSPDs must be cryogenically cooled, they are individually wired via long cables to their room-temperature interface electronics. However, the number of cables is limited due to their cost, size and the heat leaking through them that can warm up the detectors and cause malfunctions. To avoid the large number of cables, this project will demonstrate an ultra-low-power cryogenic electronic interface for detector arrays with more than 1000 channels, thus enabling future large-scale quantum computers.