Every photonic quantum computer ships with a multi-million dollar refrigerator. QC82 wants to eliminate it
A conversation with Hussain Zaidi, who is building the detector nobody thought was possible.
The most advanced machines humanity has ever built share an odd weakness: they cannot see light without being chilled to near absolute zero. Hussain Zaidi, co-founder and CEO of American startup QC82, is betting that photon detection can happen on a semiconductor chip, at room temperature. If he is right, a technology that has ruled the field for forty years becomes obsolete, and quantum computing stops being a luxury reserved for governments and tech giants.
Photonics is a mature field. What made you look at it and see an opening?
Global photonics infrastructure all around us has needed better infrared detectors for many decades now. But the last few years have been the start of an era where photonic quantum computers are being scaled up to qubit counts orders of magnitude greater than we’ve had. Non-cryogenic detection would be a game changer in the scalability of these computers.
As someone working in photonics, it was hard to miss the unusual moment: high efficiency room temperature photon detection is the key to making the present day global photonics infrastructure better as well as enabling the scalable quantum computing era of the future.
You are going up against an incumbent technology that has held the field for forty years. Why take that on?
Photonics has always been fascinating for me. When I saw a challenging open problem in photonics with the immense potential to change the world, it felt like the stars aligned: my interest, the drive to create ambitious technology, and the desire to do something marketable.
Deep tech is brutal. What was the hardest roadblock?
There were so many roadblocks and hurdles, it is hard to pick one. Perhaps a good lesson through it all is that the greatest thing needed is persistence and willingness to keep moving. We have heard many people tell us that room temperature high efficiency photon detection for quantum computing is not possible. But we believe this viewpoint comes from a narrow understanding of what quantum computers will look like in five to ten years. Moving ahead with drive and conviction in the face of naysayers is always challenging.
How would you explain the shift from cryogenic to semiconductor detection to someone who runs a business, not a lab?
Cryogenic detectors are amazing in their specs, but they are very expensive to build and run for a quantum computer. Imagine a quantum computer available to you on the cloud that has hundreds of thousands to millions of photonic qubits. That quantum computer will need a liquid Helium cryogenic plant running 24/7. With semiconductor detectors, it is possible that we don't need this cryogenic plant, resulting in the build cost and engineering complexity coming down drastically.
Just like ubiquitous AI is having a much bigger impact on our lives, more readily deployable and cost effective quantum computing will start affecting our lives in numerous ways.
“A photonic quantum computer at scale will need a liquid helium plant running 24/7. Remove that, and quantum computing opens up to organizations of all sizes.”
Which industry feels the impact first?
It is an exciting time when classical and quantum applications both need high efficiency photon detection. While the performance bar for quantum computing is high, the bar for classical photonics and communications is lower given that current infrared detectors have low detection efficiencies and high dark counts. We see LiDAR and communications as the first major markets where our detectors will change the paradigm: longer range, safer LiDAR and lower power, higher bit rate communications.
What is the team focused on right now?
We have been heads down on technical development the last few years. On the heels of state-of-the-art results, we are now looking to do industrial pilots of our technology. Successful pilot partnerships will establish us as a deep-tech startup with a long-term technical development roadmap but near-term scalable revenue.
Building on room-temperature photon detection, QC82's ambition is to develop room-temperature photonic qubit chips, becoming the critical infrastructure layer for global quantum communication networks and ultra-large industrial-scale quantum computers.
You could have taken money from many deep tech investors. Why Tensor Ventures?
One thing immediately stood out for us when we met the Tensor team: Tensor Ventures was much more interested in the technology than the hype. That was a big positive signal for us. Curiosity to understand the technical details is fantastic to have in a VC partner, and something deep tech ventures sometimes miss given other priorities. This shared interest in the technology QC82 is developing has helped us keep going and overcome many hurdles, big and small, as a team of shareholders creating value for everyone.
Tensor also has active networks in the industry, and their recommendations have been super helpful in recruiting, business development, tech development and investor outreach. Plus Roman, Martin and Petr (co-founders) are great to hang out with, and share stories over conferences and dinners in Charlottesville, Brno and Prague.
Hussain Zaidi is the co-founder and CEO of QC82. A physicist and deep tech entrepreneur, he holds a Ph.D. from the University of Virginia and did research at the Max Planck Institute in Erlangen, Germany. His career spans quantum, biotech, finance, and AI, from government-funded quantum research to commercial AI research. At QC82, he leads the team building photonic infrastructure for next-generation quantum and classical applications, with one goal: make the multi-million dollar cryogenic systems behind today's quantum computers a thing of the past.