DARPA Enters Phase 2 of Project Targeting ‘Quantum Advantage’ 

Rigetti Computing and the Universities Space Research Association or USRA on Thursday confirmed they’re kicking off the second phase of a Defense Advanced Research Projects Agency-led effort to develop next-level, quantum computers.

Building on the first phase of the Optimization with Noisy Intermediate Scale Quantum devices program, which launched in 2020, the entities are now pushing DARPA’s ONISQ further—with ultimate aims to demonstrate quantum advantage on intermediate scale quantum computers with hundreds of qubits. 

Demonstrating quantum advantage would mean proving that a quantum computer is capable of solving a problem that would essentially take forever, or an unfeasible amount of time on a classical computer.

“Specifically, the program is looking to solve a class of problems called combinatorial optimization problems,” a Rigetti spokesperson told Nextgov on Friday. “In practical terms that can be things like complex scheduling tasks, supply chain logistics or network optimization, which are important for both military and civilian operations.”

So far, the work has resulted in more than 10 scientific papers that were published or presented at international conferences, or are currently under review.

Quantum information science is an emerging field that exploits unusual physics that occurs at subatomic levels to process data and information in new and even unimaginable ways, and holds potential to introduce disruptive breakthroughs across many sectors. While the basic units of information in traditional computers are known as binary bits, quantum computers run on quibits. 

The initial phase of this DARPA-backed pursuit was conducted on Rigetti’s 32 and 40-qubit systems, and the team’s algorithm development reached a milestone called “N.p > 100.”

“This means that the number of qubits (N) multiplied by the number of operations performed on those qubits (p) is greater than or equal to 100,” Rigetti’s spokesperson explained. 

Phase 2 will begin on the company’s recently announced 80-qubit system, known as Aspen-M. And over the two and a half years-long project phase, officials also plan to leverage future systems currently in Rigetti's research and development pipeline. 

“More qubits and improved error rates will allow us to encode more information and tackle more complex instantiations of the problem, measured by higher N.p scores,” the spokesperson said. “Phase 2 also includes benchmarking the quantum algorithm against classical computers, to rigorously test whether the quantum solution in fact provides a performance enhancement over current approaches.”

They added that those involved believe that their “ability to achieve the ambitious milestones set in the first phase and advance to the second phase of the ONISQ program” was partly due to the fact that they’re using superconducting systems to power this work.

The official did not say whether ongoing supply chain challenges are impacting this initiative, but noted that Rigetti launched several new systems over the course of the first phase. 

“We own and operate Fab-1, the industry's only dedicated and integrated quantum device manufacturing facility, which allows us to design, test and [fabricate] new devices on significantly shorter timelines than third party foundries,” the spokesperson said.