PsiQuantum Bets on Photonic Qubits in Semiconductor Factories

Builds fault-tolerant quantum computers on the photonic route: uses standard semiconductor processes to make quantum photonic chips, expands them via fiber interconnects into million-qubit-class machines, and sells them to institutional customers that need computing power.

Bets that million-qubit quantum computer is a manufacturing problem, not physics; if architecture fails, company does not stand.

2025-09-10 disclosed Series E of more than $1 billion (official press release); cumulative commitments from the State of Illinois and local governments of approximately $700 million (2024 $500 million + earlier $200 million, according to Quantum Insider).

Founded in 2016 in Palo Alto, California, by Jeremy O'Brien, Pete Shadbolt and others. The bet began with a route choice: rather than struggling to improve superconducting-qubit coherence, it bet that photonic qubits could be mass-produced using the semiconductor industry's existing capacity—first small-scale validation, then scaling all the way to a million qubits.

In 2024-07, it reached agreements with the State of Illinois, Cook County, and Chicago to locate at the Illinois Quantum and Microelectronics Park (IQMP); on 2025-09-10, it announced a Series E of more than $1 billion and disclosed that the Brisbane campus in Australia was being advanced in parallel; on 2025-09-30, it broke ground at the former U.S. Steel South Works site in Chicago—first building the company's largest intermediate-scale test system, to be directly reviewed by a DARPA Quantum Benchmarking Initiative (QBI) expert panel, and then building and deploying the first million-qubit-class fault-tolerant quantum computer in the United States.

Manufacturability of photonic qubits reuses semiconductor industry, bypassing coherence and control-line problems.

Milestones are verifiable: groundbreaking, campus, Series E, DARPA review are public.

Capital is large: over $1B Series E plus $700M public investment raise stakes.

Risks remain: no million-qubit machine built, test system and DARPA review pending.

Treating quantum computing as a manufacturing problem can bypass competitors' hardest parts, but risk shifts to engineering and funding lasting until results.

As of 2026-09-01, PsiQuantum is building. Chicago IQMP Phase 1 includes an 80,000-square-foot office and R&D building with cryogenic environment. Later phases and DARPA review remain. Machine not live; fundraising and campus construction continue.