PsiQuantum

O'Brien is a physicist who held professorships in Physics and Electrical Engineering at the University of Bristol, where he founded and directed the Centre for Quantum Photonics, and later at Stanford. He demonstrated the first photonic two-qubit logic gate, invented integrated quantum photonics as a field, and co-invented the Variational Quantum Eigensolver (VQE) — work spanning 150 papers with over 40,000 citations (h-index 88). He co-founded PsiQuantum in 2016 to build a fault-tolerant quantum computer using silicon photonics manufactured in conventional semiconductor foundries, and transitioned from CEO to Executive Chairman in early 2026.

Rudolph is a quantum information theorist who held a Royal Society University Research Fellowship and a professorship at Imperial College London before co-founding PsiQuantum in 2016. He is known for co-developing the Raussendorf-Harrington-Goyal (RHG) lattice and the concept of topological cluster states, foundational results in measurement-based quantum computing. His theoretical framework for fault-tolerant photonic quantum computation — which enables quantum error correction using linear optics and photon detection — forms the architectural backbone of PsiQuantum's approach.

Shadbolt earned his DPhil from the University of Bristol in Jeremy O'Brien's quantum photonics group, working on integrated photonic circuits for quantum information experiments. He was a research fellow at the same institution before co-founding PsiQuantum in 2016. As CSO he oversees the scientific research programme underlying PsiQuantum's silicon photonics approach, including photon source development, photonic chip design, and error correction protocols aimed at delivering the first utility-scale fault-tolerant quantum computer.

Thompson was a professor and researcher in integrated quantum photonics at the University of Bristol, where he co-led silicon photonics research within the Centre for Quantum Photonics alongside Jeremy O'Brien and Pete Shadbolt. His work focused on fabricating photonic integrated circuits for quantum computation and quantum communication. He co-founded PsiQuantum in 2016 and, as Chief Technologist, leads the engineering teams responsible for translating quantum photonic research into manufacturable silicon chip designs produced at GlobalFoundries.