DARPA announces US2QC to test underexplored paths to utility-scale quantum computing

Challenging the prevailing view that practical, fault-tolerant quantum computers are decades away, DARPA has announced a new program to scrutinize whether underexplored approaches could deliver utility-scale systems much sooner.

The Underexplored Systems for Utility-Scale Quantum Computing (US2QC) program aims to determine if any unconventional architecture can achieve a “truly useful, really big, fault-tolerant quantum computer” on a faster timeline than conventional predictions. “DARPA’s mission is to create and prevent strategic surprise,” said Joe Altepeter, US2QC program manager in DARPA’s Defense Sciences Office.

“If there’s an underexplored area of quantum computing showing promise for a faster breakthrough than we previously expected, we want to explore it immediately and thoroughly verify and validate the approach’s viability.” US2QC complements an existing effort, Quantum Benchmarking, which is developing quantitative metrics on the software side to evaluate where quantum machines could provide meaningful advantages over classical computers.

While Quantum Benchmarking focuses on applications, US2QC centers on hardware—verifying and validating system, component, and subsystem designs for a proposed fault-tolerant quantum computer. DARPA is inviting companies and organizations that believe they can build such a machine to make their case.

“We would like them to show us exactly why they’re convinced their machine is going to be revolutionary in the near future, and we want to work collaboratively with them, pay for additional experts to embed with their team, and help advance bold concepts that withstand rigorous testing,” Altepeter said.

Because quantum hardware approaches vary widely, the agency is structuring US2QC for maximum flexibility and will exclusively use tailorable Other Transaction agreements to fund proposals. Every team will begin with a Phase 0: a quantitative description of a complete utility-scale concept, including all components and subsystems, projected performance across multiple metrics, and anticipated technical risks with mitigation strategies.

“There’s no one verification and validation program that fits all the different quantum computing approaches out there,” Altepeter said. As a result, the content and duration of follow-on phases will be customized to each project based on Phase 0 validation and verification.

If a concept proves sound, Phase 0 could be brief, and the effort will scale as teams meet milestones unique to their approach. The program’s goal is not to pick a winner in quantum computing, but to rigorously test whether any less-studied pathway can credibly accelerate the arrival of utility-scale, fault-tolerant systems—and to do so with clear metrics, embedded expertise, and staged milestones.