Google makes advance in universal quantum computing

Nature : Researchers at Google have developed a prototype quantum computer that improves on earlier designs by combining analog and digital approaches. It is based on adiabatic quantum computing (AQC), in which a group of qubits is encoded with a computational problem and then subjected to gradually changing external conditions. The system arrives at a solution by adapting and adjusting its collective quantum state. Although any problem can be encoded in such an AQC system, errors are rife due to random noise. To correct that problem, the researchers have added digitized quantum computing to take advantage of digital circuits’ ability to systematically correct errors. Google’s prototype device consists of a superconducting circuit of nine aluminum qubits deposited on a sapphire surface and cooled to 0.02 K. Although the device comprises just a few qubits, a scaled-up version could be used to solve computational problems too complex for classical computers, such as simulating molecules and materials at the quantum level.