QuiX Quantum, a deep tech scale-up from the Netherlands and part of the EIC Scaling Club’s Next-Gen Computing group, has reported a major step towards practical, scalable quantum machines: “below-threshold” error mitigation demonstrated on a photonic quantum computer.

In plain terms, the team showed a hardware-ready way to reduce physical errors early enough that scaling to larger, fault-tolerant systems becomes more realistic. That matters because quantum information is inherently fragile: without effective error reduction and correction, useful computations break down as systems grow.

“Below-threshold, physical error mitigation has never been implemented in a photonic quantum computer. This achievement marks a significant milestone and places QuiX Quantum at the forefront of progress toward fault-tolerant photonic quantum computing,” said Stefan Hengesbach, CEO of QuiX Quantum. “We believe the most resource-efficient strategy is to reduce errors early rather than correct them at great expense — and by demonstrating net positive error mitigation on real hardware, we’ve taken a foundational step that showcases European leadership in accelerating quantum technologies toward powerful, large-scale systems.”

The approach: photon distillation at the hardware level

Photonic quantum computers encode information in photons (particles of light) moving and interfering on an optical chip. A persistent challenge is that real-world photon sources are imperfect: tiny differences between photons can leak “which-path” information, degrading entanglement and introducing distinguishability errors.

QuiX Quantum’s work focuses on photon distillation, a coherent, hardware-level technique that improves single-photon quality before the computation begins. Instead of relying on heavy redundancy or extensive classical post-processing, photon distillation uses quantum interference among multiple imperfect photons to output a cleaner photon that is more indistinguishable.

What the team demonstrated and why it matters

Using a programmable 20-mode photonic processor, the team implemented a photon distillation gate and reported:

• a 2.2× reduction in photon indistinguishability error (photons became measurably more alike); and
• a 1.2× net reduction in total error even after accounting for additional noise introduced by the gate.

Beyond the immediate experimental result, the research suggests a practical systems benefit: combining photon distillation with quantum error correction could significantly cut resource requirements. Based on modelling with current photon-source performance and photonic architectures, the approach could reduce the number of photon sources required per logical qubit by up to a factor of four – potentially lowering complexity, cost and engineering overhead.

The project was conducted on the QuiX Bia Cloud Quantum Computing Service in collaboration with NASA’s Quantum Artificial Intelligence Laboratory, the University of Twente and Freie Universität Berlin, and was partially funded through the Netherlands Ministry of Defense’s Purple NECtar Quantum Challenges initiative. The findings are described in an arXiv preprint (arXiv:2601.05947) that is undergoing peer review.

About the EIC Scaling Club

The EIC Scaling Club is a curated community where 120 European deep tech scale-ups with the potential to build world-class businesses and solve major global challenges come together with investors, corporate innovators and other industry stakeholders to spur growth.

The top 120 European deep tech companies have been carefully selected from a pool of high-growth scale-ups that have benefitted from EIC financial schemes, other European and national innovation programmes, and beyond.

The EIC Scaling Club is an EIC-funded initiative run in partnership by Tech Tour, Bpifrance (EuroQuity), Hello Tomorrow, Tech.eu (Webrazzi), EurA and IESE Business School.

Subscribe to our newsletter here to stay up-to-date!