Connects early optical quantum-gate experiments with the effort to manufacture large photonic quantum computers, now guiding PsiQuantum’s strategy and partnerships as executive chairman.
arXiv / NaturePsiQuantumO’Brien’s work spans the laboratory demonstration of an optical logic gate and the organization of a company around photonic quantum computing. The controlled-NOT experiment is a specific early result: it produced entangled photon states using an optical circuit, with limitations inherent to its probabilistic operation. PsiQuantum extends the photonic approach toward semiconductor manufacturing and large systems. His February 2026 move to executive chairman identifies a strategic role; it should not be confused with an ongoing chief executive title.
PsiQuantumarXiv / NatureDefining contributions
Work, in context- 2003
Demonstrating an optical controlled-NOT gate
Coauthored an all-optical controlled-NOT gate experiment that produced all four Bell states. The demonstrated gate was probabilistic, an important qualification for its use in scalable computation.
Coauthor of the probabilistic optical controlled-NOT experiment; shared experimental credit.
Source-supported recordarXiv / Nature - 2016
Co-founding PsiQuantum
Helped found PsiQuantum to pursue large-scale photonic quantum computing. In February 2026 he became executive chairman, with responsibilities spanning strategy, the board and key partnerships.
Company co-founder and executive chairman; strategic and board responsibilities rather than sole hardware invention.
Source-supported recordPsiQuantum
Keep in perspective
Company-scale goals are presented as an ongoing effort, not as a delivered fault-tolerant computer.
Follow the evidence
2 sourcesPrimary papers, institutional records and attributed announcements. Each source supports the claims linked above.
- PsiQuantumCompany announcement
PsiQuantum Appoints Victor Peng as Interim CEO, Co-Founder Jeremy O’Brien to Become Executive Chairman
Executive-chairman appointment, company founding and strategic responsibilities
Published 2026-02-10 · Checked 2026-09-19 - arXiv / NatureResearch paper
Demonstration of an all-optical quantum controlled-NOT gate
Coauthorship and experiment; journal publication Nature 426, 264 (2003)
Published 2004-03-08 · Checked 2026-09-19