In a first, researchers have shown that adding more “qubits” to a quantum computer can make it more resilient. It’s an essential step on the long road to practical applications.

How do you construct a perfect machine out of imperfect parts? That’s the central challenge for researchers building quantum computers. The trouble is that their elementary building blocks, called qubits, are exceedingly sensitive to disturbance from the outside world. Today’s prototype quantum computers are too error-prone to do anything useful.

In the 1990s, researchers worked out the theoretical foundations for a way to overcome these errors, called quantum error correction. The key idea was to coax a cluster of physical qubits to work together as a single high-quality “logical qubit.” The computer would then use many such logical qubits to perform calculations. They’d make that perfect machine by transmuting many faulty components into fewer reliable ones.

“That’s really the only path that we know of toward building a large-scale quantum computer,” said Michael Newman(opens a new tab), an error-correction researcher at Google Quantum AI.

...read more at quantamagazine.org