Google breakthrough paves way for large-scale quantum computers

If a small quantum computer makes a small number of errors, will a large quantum computer make even more errors, making it completely useless? No, say researchers at Google who have made a key breakthrough in error correction for quantum devices, setting out a theoretical path to creating machines that are useful and practical.

Ordinary computers store data as bits that are either a 0 or 1, but errors can cause the bit to “flip” to the wrong value, which is why devices from smartphones to supercomputers have built-in error correction.…