Silicon photonic platform supports room-temp quantum computing

Artilux Inc. (Zhubei, Taiwan) has collaborated with academic Richard Soref from The University of Massachusetts to investigate quantum information processing on an integrated silicon photonics platform.

Artilux, founded in 2014, has been a pioneer of germanium-silicon photonics and CMOS-based SWIR (short-wavelength infrared) single photon detection. The first result of the collaboration has been a paper published in APL Quantum entitled Room-temperature photonic quantum computing in integrated silicon photonics with germanium–silicon single-photon avalanche diodes.

Existing photonic quantum computing architectures rely on superconducting nanowire single-photon detectors (SNSPDs) based on superconductors such as niobium nitride (NbN) operated at a temperature less than 4K. Such cryogenic cooling consumes a great deal of power and limits use outside of specialized facilities.

Artilux has proposed the replacement of SNSPDs with a waveguide-based germanium-silicon single-photon avalanche diode (SPAD) that was written up in Nature in February 2024

The APL Quantum paper shows that by combining on-chip waveguided spontaneous four-wave mixing sources, waveguided field-programmable interferometer mesh circuits, and a waveguided spatially-multiplexed array of photon-number-resolving GeSi SPADs detectors with a proper gating window, a highly integrated electronic-photonic system capable of being operated outside cryogenic environment can be realized.

Researchers have also shown that simulated room-temperature GeSi SPAD designs could outperform current NbN SNSPD based designs.

“Cryogenic modules are presently used in all photonic quantum computers and in many photonic quantum information applications, and we expect that such modules can be eliminated after experimental R&D on photonic integrated circuits and their associated electronic circuits confirms our predictions of performance metrics that are fully equivalent to those of the present art,” said Richard Soref, in a statement issued by Artilux.

The use of room-temperature SPADs could be applicable to quantum computation, quantum communication, quantum sensing and quantum imaging. As the demand for quantum technology grows, this innovative approach has the potential to accelerate widespread adoption, bringing the future of RT quantum computing closer to reality.