Hello. Le 31/03/2016 22:04, Scott Pakin a écrit :
My institution just bought a D-Wave 2X adiabatic quantum computer. The problem is, no one really has a grasp on how to *program* an adiabatic quantum computer. It's a totally different beast from the gate-model quantum computers that most people imply when they talk about quantum computing. I find all this a bit disturbing... Los Alamos buys an expensive device that nobody knows how to use??
Moreover, in circumstances where the doubts about the real performance of the D-Wave computer stii persist? Several physicists refuse to call this contraption a "quantum computer". The statements about their "qubits" in their public materials are not always serious, there is practically nothing about a genuine state superposition, no educated physicist will buy such pseudo-definition as "having simultaneously the values 0 and 1" (being the result of two currents flowing in opposite directions ; what about phase?). Their "white paper" about the map colouring shows a model which is more similar to a Hopfield (or similar) neural network, rather than a quantum computing device. The optimization is a natural application domain of such networks, but where are some more universal examples? Surely, there are quantum elements in it: superconducting niobium rings, Josephson junctions, etc. But, actually, even a plain transistor is a quantum device as well, and nobody dares to call it a "qubit". Their native code seems to be extremely far from quantum theory, as we know it. = But, if the device works, has some affinities with neural stuff and with Monte-Carlo techniques (annealing), perhaps a good playground for testing it would be a Go player? Jerzy Karczmarczuk