Google says its D-Wave quantum computer works

MIT Technology Review : In 2013 Google’s Quantum AI Lab purchased one of D-Wave’s quantum computers. The effectiveness of the computers has been controversial . In a paper that the company posted online, Google describes its work with the machine and suggests that some of D-Wave’s claims about its computer may be accurate. Working with NASA, Google compared the effectiveness of the D-Wave machine against a conventional computer running an algorithm that attempts to reproduce the quantum annealing process used by the D-Wave computer. According to Hartmut Neven of Google, for solving the very specifically designed problems that the computers were given, the D-Wave machine was 100 million times faster than the conventional machine. That suggests the D-Wave computer is making use of quantum tunneling to find the solutions more effectively than the conventional computer. However, a conventional machine running a different algorithm likely could have at least equaled the speed of the D-Wave machine.