According to researchers the D-Wave Two device, the first commercially available quantum computer made by Canadian company D-Wave Systems Inc., was found to have no significant perfomance improvements over the classic PC it is trying to replace.

Classical computers perform calculations using bits, whose value can only be 0 or 1. Quantum computers instead use quantum bits, or "qubits," that can exist as a 0 and 1 at the same time. This allows quantum devices to perform multiple calculations at once.

Theoretical physicist Richard Feynman was one of the first to propose the idea of quantum computers in the 1980s, as a way to overcome the limitations of classical computers in simulating quantum systems in physics. Later, mathematician Peter Shor showed that a quantum computer could factor an integer into prime numbers, an ability that could be used to crack encryption algorithms on the Internet.