'It shows how to integrate the millions of qubits needed to realise the true promise of quantum computing.'

Building such a universal quantum computer has been called the 'space race of the 21st century'.

For a range of calculations, they will be much faster than existing computers, and for some challenging problems they could find solutions in days, maybe even hours, when today's best supercomputers would take millions of years.

The full findings were published in the journal Nature Communications.