- DARPA adds four companies to Phase C of the Quantum Benchmarking Initiative.
- Quantum computers use qubits, which can store multiple values simultaneously, offering significant advantages.
- QBI comprises three phases, with the goal of realizing a fault-tolerant quantum computer.
- The four companies are each employing different quantum computing approaches for testing.
The U.S. Defense Advanced Research Projects Agency (DARPA) has added Atom Computing, Diraq, IonQ and IBM to the Phase C verification of its Quantum Benchmarking Initiative (QBI). Entry into Phase C means these companies will begin physical testing of their fault-tolerant quantum computing (FTQC) architectures, with the initiative planning to launch an industrial-scale quantum computer in 2033. Quantum computing is considered the next frontier in computing, with the potential to help solve problems in drug discovery, materials research and climate change.
Traditional computers use binary bits that can store only the values 0 and 1, while quantum computers use quantum bits (qubits), which can store multiple values between 0 and 1 simultaneously and even perform parallel computation. This offers significant advantages but also presents a new computational challenge: the accumulation of large numbers of errors. Scientists can create qubits in various ways, but high error rates remain the primary constraint on large-scale quantum computers. QBI is testing whether these computers can be delivered by 2033.
QBI's Three Phases
QBI comprises three phases, each a critical milestone toward developing a fault-tolerant quantum computer. Phase A evaluates utility-scale quantum computing concepts to determine whether they can be realized in the near term. Participants advancing to Phase B submitted research and development plans to DARPA outlining the risks of their chosen approaches and planned mitigation measures. In Phase C, participants will verify and validate their FTQC architectures through physical testing, system measurement and empirical verification, in collaboration with the government. This is neither a competition to evaluate the best quantum computing technology nor a collaborative effort among companies.
The program's primary objective is to determine which approaches can reach utility scale by 2033, meaning the computational output value of the quantum system exceeds its capital and operating expenditures.
Each Company's Approach
Currently, DARPA has added four companies to Phase C, while Microsoft and PsiQuantum are already participating in a pilot program with similar goals as part of the "Underexplored Systems for Utility-Scale Quantum Computing" (US2QC) effort. Each company now in Phase C employs a different quantum computing approach.
Atom Computing uses neutral atoms as qubits; its proposed system comprises an array of more than 1,200 optically trapped neutral atoms. Diraq uses silicon spin qubits — single electrons trapped in tiny electrostatic gates. The company is seeking to validate its foundry-fabricated 300-millimeter wafers, with a target of placing more than two million physical qubits on a single chip by 2031. IonQ uses trapped ions as qubits and recently unveiled its Superion 256 quantum processing unit (QPU), a device designed to fit in a server rack; it will assess whether its manufacturing practicality aligns with its utility-scale goals.
IBM is taking a full-stack approach to quantum computing, using transmon qubits for its quantum computing hardware while developing open-source software to operate that hardware and make it accessible via the cloud.
"The field of quantum computing is advancing rapidly, and we increasingly expect that someone will build a utility-scale quantum computer before 2033," QBI Executive Director Micah Stoutimore said in a press release. "We do not yet know which team or technical approach will achieve this goal. Therefore, QBI is evaluating each path on its merits and continuing to bring in promising new approaches."
The Future and Challenges of Quantum Computing
Quantum computing is viewed as key to the future of computing, capable of solving a variety of complex problems. DARPA's QBI program is not only a driver of technological development but also a major milestone in the commercialization of quantum computing. Despite the current challenge of high error rates, companies are conducting physical tests via diverse technical paths, demonstrating the industry's diversity and competitiveness. These efforts will help identify the most effective quantum computing methods and drive them toward utility scale in the future, ultimately advancing technological progress and applications.