PsiQuantum, a US-based quantum computing company, has secured $1bn in Series E funding to accelerate the development of fault-tolerant quantum computers.

This funding round was led by affiliates of BlackRock with contributions from Temasek and Baillie Gifford. It values PsiQuantum at $7bn and introduces new investors, including entities managed by Macquarie Capital and Ribbit Capital.

This investment aims to support the establishment of utility-scale quantum computing sites in Brisbane, Australia and Chicago and will aid in the deployment of large-scale prototype systems. It further aims to advance PsiQuantum’s quantum photonic chips and architecture.

PsiQuantum’s approach is driven by its focus on error correction, which it believes necessitates around a million physical qubits to achieve commercially viable quantum computing. The company aims to address significant challenges such as manufacturability, cooling, and networking by leveraging the advantages of photonic qubits alongside semiconductor manufacturing processes.

PsiQuantum co-founder and CEO Jeremy O’Brien said: “Only building the real thing—million-qubit-scale, fault-tolerant machines—will unlock the promise of quantum computing.

“We defined what it takes from day one: this is a grand engineering challenge, not a science experiment. We tackled the hardest problems first—at the architectural and chip level—and are now mass-manufacturing best-in-class quantum photonic chips at a leading US semiconductor fab.

“With this funding, we’re ready to take the next decisive steps to deliver the full potential of quantum computing.”

Since its Series D funding in 2021, PsiQuantum has established a high-volume manufacturing process for its photonic chipset at GlobalFoundries’ facility in New York.

A critical development is the integration of Barium Titanate (BTO) into its production line. BTO plays a crucial role in optical switches necessary for scaling optical quantum computing. The latest funding is expected to help the firm to further scale up the production of BTO towards the volumes required for utility-scale quantum computing.

PsiQuantum manufactures BTO wafers in California before integrating them with those produced at GlobalFoundries.

Nvidia’s venture capital arm, NVentures, is also among the new investors in PsiQuantum. The quantum company has also entered into a partnership with Nvidia, which spans several areas, including quantum algorithms, software development, and graphics processing unit (GPU)-quantum processing unit (QPU) integration.

This collaboration supports advancements in PsiQuantum’s silicon photonics platform. Additionally, the firm is said to be actively working on systems that do not rely on traditional cryostats. Instead, it has developed a high-density cooling solution similar to data centre racks, capable of accommodating multiple quantum chips.

Earlier in 2025, PsiQuantum completed the research phase of US Defense Advanced Research Projects Agency’s (DARPA) Underexplored Systems for Utility-Scale Quantum Computing (US2QC) programme. The project now moves into the validation phase under DARPA’s Quantum Benchmarking Initiative.

This phase will evaluate system design, component performance, and application use cases, marking a significant step towards realising commercially viable quantum computing systems.