Jeremy O’Brien, Mark Thompson, Terry Rudolph, Pete Shadbolt
C4 Ventures team
PsiQuantum was founded in 2016 and is headquartered in Palo Alto, California. The company’s mission is to build and deploy the world’s first useful quantum computers. PsiQuantum’s photonic approach enables it to leverage high-volume semiconductor manufacturing, existing cryogenic infrastructure, and architectural flexibility to rapidly scale its systems.
How We Met & Why We Invested
Pascal Cagni first met PsiQuantum Co-Founder and CEO Jeremy O’Brien in New York in 2019, before traveling to Silicon Valley to meet CSO & Co-Founder Pete Shadbolt. At the time, quantum computing was still largely considered a scientific curiosity rather than a future industrial reality.
Together with Michel Sassano and Boris Bakech, the team at C4 Ventures developed a strong conviction that quantum computing would become a foundational layer of next-generation computing infrastructure. Among the few companies pursuing a credible path toward fault-tolerant quantum computing at scale, PsiQuantum distinguished itself through the exceptional depth of its scientific expertise combined with a highly ambitious industrial and engineering vision.
C4 Ventures invested early in PsiQuantum based on the belief that building a commercially viable quantum computer would require not only scientific breakthroughs, but also the ability to industrialize and scale advanced photonic technologies over the long term.
In September 2025, PsiQuantum announced a $1 billion Series E financing round valuing the company at approximately $7 billion. The funding supports the company’s ambition to build the world’s first million-qubit fault-tolerant quantum computer, including the deployment of large-scale quantum computing sites in Brisbane and Chicago, the expansion of its California facility, and the industrialization of advanced materials and optical quantum chipsets.
Pascal Cagni and PsiQuantum's CSO & Co-Founder Pete Shadbolt, Silicon Valley, 2019
Pete Shadbolt (in the middle) with C4 Ventures teams (from left to right): Boris Bakech, Co-Founder & Managing Partner; Michel Sassano, Partner; Jean Weill, Associate
Omega, a quantum photonic chipset purpose-built for utility-scale quantum computing
