D-Wave claims to have built its largest-ever quantum chip

Davide Castelvecchi

John A. Smolin, Graeme Smith

Sebastian D. Pinski

Adiabatic Quantum Computing (AQC) is a relatively new subject in the world of quantum computing, let alone Physics. Inspiration for this project has come from recent controversy around D-Wave Systems in British Columbia, Canada, who claim to have built a working AQC which is now commercially available and hope to be distributing a 1024 qubit chip by the end of 2008. Their 16 qubit chip was demonstrated online for the Supercomputing 2007 conference within which a few small problems were solved; although the explanations that journalists and critics received were minimal and very little was divulged in the question and answer session. This 'unconvincing' demonstration has caused physicists and computer scientists to hit back at D-Wave. The aim of this project is to give an introduction to the historic advances in classical and quantum computing and to explore the methods of AQC. Through numerical simulations an algorithm for the Max Independent Set problem is empirically obtained.

Jacob Aron

The quantum revolution is still in the slow lane. The first head-to-head speed test of the D-Wave Two, the commercial quantum computer recently purchased by Google, suggests that the machine performs no better than an ordinary PC. In theory, quantum computers are capable of calculating answers to problems much faster than standard PCs. Instead of storing information in bits as either 0s or 1s, quantum machines use quantum bits, or qubits, that can be both 0 and 1 at the same time. So far, however, the quantum devices built in labs can only support a handful of qubits, which limits their speed. Now a team led by Matthias Troyer of ETH Zurich in Switzerland has tested a D-Wave Two computer against a conventional machine running an optimized algorithm and found no evidence of superior performance in the quantum device.