DARPA-Backed Researchers Develop New Quantum Circuit With Logical Qubits

The Defense Advanced Research Projects Agency announced on Wednesday that its Optimization With Noisy Intermediate-Scale Quantum Devices program has produced the first quantum circuit with logical quantum bits.

The development could accelerate fault-tolerant quantum computing and transform quantum processor design, DARPA said Wednesday.

A Harvard University team supported by the California Institute of Technology, the Massachusetts Institute of Technology, Princeton University and QuEra Computing made the breakthrough. DARPA tasked the team and others to explore different types of physical and non-logical qubits as part of ONISQ.

The Harvard team developed techniques to produce error-correcting logical qubits with arrays of Rydberg atomic qubits, which Mukund Vengalattore, ONISQ program manager at DARPA’s Sciences Office, described as behaviorally indistinguishable from one another. Rydberg qubits’ homogeneity allows them to scale rapidly and be configured on a chip while avoiding errors in the process, he explained.

According to Vengalattore, ONISQ facilitated collaboration between the quantum sensing and quantum information science communities that expedited the Rydberg qubit breakthrough.