Google hailed key milestones in its development of quantum technology, with its latest chip Willow performing a compute function in a fraction of the time a traditional machine would take and delivering an exponential reduction in errors.

Hartmut Neven, founder and lead of Google Quantum AI, blogged about Willow’s accomplishment in performing a standard benchmark computation in less than five minutes, explaining this would take even the fastest current machines 10 septillion years.

The time a machine of today would take “vastly exceeds the age of the universe”, Neven wrote.

Neven explained Willow provides a significant advance in Google’s goal to “build a useful, large-scale quantum computer”, a journey commenced in 2012.

Testing
The benchmark involved was random circuit sampling, a process other Google researchers have previously explained offer some small guarantees regarding computational abilities by comparing quantum processors with the most cutting-edge machines of today.

Neven wrote the approach is “the classically hardest benchmark” a quantum computer can currently run.

“You can think of this as an entry point for quantum computing, it checks whether a quantum computer is doing something that couldn’t be done on a classical computer.”

Neven added Google’s work with one of the most-powerful classic supercomputers shows the gap between their capabilities and quantum processors is growing at “a double exponential rate”.

Calculating
The reduction in errors is an important element in the Willow benchmark.

Neven explained the qubit unit of computation power employed in quantum machines are prone to errors due to the speed with which information is exchanged.

In a related article, Google specialists explained they upped the correctional capabilities of Willow by grouping qubits together into a surface which is more tolerant to errors.

The bigger the surface gets, the greater its ability to resist errors.

Neven explained the Willow test began with a surface of 3×3 encoded qubits, which it increased in stages to a size of 7×7 and, in turn cut the error rate in half.

“This historic accomplishment is known in the field as below threshold, being able to drive errors down while scaling up the number of qubits.”

“You must demonstrate being below threshold to show real progress on error correction”.

Neven noted other “firsts” in the Willow test involving “real-time error correction on a superconducting quantum system” and the fact it was “beyond breakeven” because its qubit arrays “have longer lifetimes” than individual units, “an unfakeable sign that error correction is improving the system overall”.

The Google engineer told BBC News it was unlikely a commercial quantum chip would be released before the end of the decade, with the outlet also noting other specialists offered a dose of realism over the company’s latest achievement, pointing out it involved a single, specialised test.