A manufacturable platform for photonic quantum computing
PsiQuantum team, Koen Alexander, Avishai Benyamini, Dylan S. Black, Damien Bonneau, Stanley P. Burgos, Ben M. Burridge, Hugo V. Cable, Geoff Campbell, Gabriel Catalano, Alejandro Ceballos, Chia‐Ming Chang, Sourav Sen Choudhury, C. J. Chung, Fariba Danesh, Tom Dauer, Michael W. Davis, Eric F. Dudley, Ping Er-Xuan, Josep Fargas · Nature · 2025
Abstract Although holding great promise for low noise, ease of operation and networking 1 , useful photonic quantum computing has been precluded by the need for beyond-state-of-the-art components, manufactured by the millions 2–6 . Here we introduce a manufacturable platform 7 for quantum computing with photons. We benchmark a set of monolithically integrated silicon-photonics-based modules to generate, manipulate, network and detect heralded photonic qubits, demonstrating dual-rail photonic qubits with 99.98% ± 0.01% state preparation and measurement fidelity, Hong–Ou–Mandel (HOM) quantum interference between independent photon sources with 99.50% ± 0.25% visibility, two-qubit fusion with 99.22% ± 0.12% fidelity and a chip-to-chip qubit interconnect with 99.72% ± 0.04% fidelity, conditional on photon detection and not accounting for loss. We preview a selection of next-generation technologies: low-loss silicon nitride (SiN) waveguides and components to address loss, as well as fabrication-tolerant photon sources, high-efficiency photon-number-resolving detectors (PNRDs), low-loss chip-to-fibre coupling and barium titanate (BTO) electro-optic phase shifters for high-performance fast switching.