Google unveils its Willow quantum chip

Google has unveiled Willow, a quantum processor with 105 qubits. According to the company, the chip demonstrates an exponential reduction in errors as the number of qubits grows, a key problem scientists have been working on for almost 30 years.

Google said Willow performed a benchmark computation in under five minutes. One of today's most powerful supercomputers would need 10 septillion years for it.

The results were published in the journal Nature. Independent experts call the error correction an important step but stress that practically useful quantum computers are still a long way off.

Shares in parent company Alphabet rose by more than 5% after the announcement.