One of the problems with the quantum world is that, as soon as you start to investigate it, conditions change and things aren't what they seem – some would say can't be what they seem. Schrodinger and his cat sum it all up nicely.
So, as soon as you ask whether D-Wave's computer is actually a quantum computer, things start going wobbly. One thing is certain; D-Wave is pushing the boundaries of computing technology.
In its latest announcement, the company says it has broken the 1000 qubit barrier; qubits are, of course, the basic computing element in a quantum computer and take advantage of such effects as superposition – which means they can represent a 0 and a 1 simultaneously – and entanglement.
The argument about whether D-Wave's machine is actually a quantum computer centres around whether or not it performs a process called quantum annealing or simulates it. It's here where things start to get a bit complicated.
Last year, Professor Matthias Troyer from ETH Zurich said: "D-Wave is an analogue device, a prototype that can be used to solve optimisation problems. It would be more accurate to describe it as a programmable quantum simulation experiment. D-Wave is certainly not a universal quantum computer."
Nevertheless, D-Wave has pushed the boundaries again with its 1000 qubit machine, which features 128,000 Josephson tunnel junctions. These devices, with six layers of metal and 0.25µm features, are said to be the most complex superconductor integrated circuits yet built.
The beauty of machines like this is in the eye of the beholder. While the likes of Google, NASA and Lockheed-Martin are in D-Wave's camp, others think you can achieve the same results using a desktop computer.
Here are two quotes from legendary physicists. Richard Feynman once said 'I think I can safely say that nobody understands quantum mechanics'. Niels Bohr noted 'anyone who is not shocked by quantum mechanics has not fully understood it'.
I'm not going to argue with either.
