Design of germanium-silicon diode points to room-temperature future of quantum photonics
Design of germanium-silicon diode points to room-temperature future of quantum photonics lead image
Most types of photonic quantum computing (PQC) architectures rely on superconducting nanowire single-photon detectors (SNSPDs) based on superconductors such as niobium nitride (NbN) operated at a temperature less than 4 Kelvin. Such cryogenic cooling requirements, however, make testing new systems slow and expensive, and the power requirements significantly limit wider use outside of specialized datacenters.
Using on-chip waveguided spontaneous four-wave mixing sources and waveguided field-programmable interferometer mesh circuits, Na et al. designed a germanium-silicon (GeSi) single-photon avalanche diode (SPAD) that is predicted to be capable of competing at room temperature with its cryogenic counterpart.
“Room temperature PQC is an example wherein room-temperature GeSi SPADs can compete with cryogenic NbN SNSPDs,” said author Neil Na. “There will be many more such application cases in the field of integrated quantum photonics for quantum information processing, such as quantum communication, quantum sensing, and quantum imaging.”
Photonics is seen as a promising avenue for most cost-effective and sustainable quantum computing because the only component that requires cryogenics is the SNSPD, a detector typically made from superconducting material such as NbN for its higher critical temperature.
The design circumvents the need for NbN SNSPDs by adopting a spatially-multiplexed M-fold-waveguide array of M GeSi SPADs to form photon-number-resolving detectors.
When benchmarked to NbN SNSPD designs, the group found that the simulated room-temperature GeSi SPAD designs might even perform better than the current state-of-the-art.
“This work will stimulate successful development of the room-temperature waveguide-integrated GeSi SPAD with photon-number-resolving capability for PQC,” Na said. “This, in turn, will lead to successful commercialization of room-temperature PQC, offering faster upgraded computation, lower cost, and lower energy consumption than the present cryogenic PQC.”
Source: “Room-temperature photonic quantum computing in integrated silicon photonics with germanium-silicon single-photon avalanche diodes,” by Neil Na, Chou-Yun Hsu, Erik Chen, and Richard Soref, APL Quantum (2024). The article can be accessed at https://doi.org/10.1063/5.0219035 .
