Quantum computation in diamond

Computers do not necessarily have to perform error-free calculations in order to provide perfect results – they only need to correct their errors in a reliable way. And this will become even more important in the future, when it is hoped that quantum computers will solve some tasks several times faster than conventional PCs with computing processes that are very efficient but also prone to disturbances.

An international team headed by physicists from the University of Stuttgart and the Stuttgart Max Planck Institute for Solid State Research has now found a way to control the quantum system of a diamond with a small number of nitrogen impurities particularly well (see paper in Nature: "Quantum error correction in a solid-state hybrid spin register"). The researchers can thus specifically address quantum bits, i.e. the smallest computing units of a quantum computer, in the diamond and combine several bits to a computing register. They use the new degree of control for a logic operation, which is essential for a quantum computer, and for error correction.