https://www.sciencedaily.com/releases/2018/11/181105160855.htm

The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least at a handful of selected tasks. The numerous advances notwithstanding, today's quantum information processors still struggle to cope with errors, which inevitably occur in any calculation. This inability to efficiently rectify errors hinders in turn efforts towards sustained large-scale processing of quantum information. Hence the excitement for a set of experiments in which the group of Jonathan Home at the Institute for Quantum Electronics integrated for the first time a range of elements needed for performing quantum error correction in a single experiment. These results have been published today in the journal Nature.

Just like their classical counterparts, quantum computers are built from imperfect components, and they are far more sensitive to disturbances from the outside. This leads inescapably to errors as calculations are executed. For conventional computers, there exists a well-established tool kit for detecting and correcting such errors. Quantum computers will rely even more on locating and fixing errors. This requires conceptually different approaches that take into account that information is encoded in quantum states. In particular, reading out quantum information repeatedly without disturbing it, as is needed for detecting errors, and reacting in real time to reverse these errors pose considerable challenges.