Uncertainty about quantum computing?
Well, it's quantum, innit?
The evidence seems to be stacking up in favour of D-Wave's claims to be offering the world a kind of quantum computer, but merely exhibiting a quantum behaviour might not be enough for the company to turn the computing world upside down. The latest news, which broke late last week, is that tests at the University of Southern …
Sounds like there are homeopathic amounts of quantum involved.
Where's Professeur Jacques Benveniste?
Or are the El Reg hacks also scratching their heads and just providing commentary on press releases?
Did you miss the part where someone outside the D-Wave group who is qualified to comment on the issue was invited to do so? He also made a pretty straight-forward explanation as to what the processor's limitations are.
I want to know how it works at all. I understand a conventional processor, how does the quantum bit come into it? My best guess is that it's using quantum states instead of larger bit-storage mechanisms but how it does that in a stable manner and how the state is then determined is beyond my present understanding, which I'm seeking to extend.
Simples. You encode the problem in an analog formulation involving a "start" hamiltonian which is slowly and linearly replaced during the computation by a "target" hamiltonian so that at the end of the computation, as the system settles into its lowest energy state, the bits encode the solution you want. The thing gets problematic as the D-Wave machine is not using full entanglement across all its bits (so it's not actually matching the mathematical idea), there is noise, it does some proprietary magic and actually finding the solution may take exponentially long in the end as the lowest energy point lies in a very flat landscape. Or something.
Maybe this will help: An introduction to quantum annealing
I hate this "omg this is quantum" - the keyboard at my desk works due to quantum mechanics: were it not for the Pauli Exclusion Principle my fingers would go right through the keys!
Quantum mechanics is why my water bottle is clear(ish), why my monitor emits light, why my chrome badge clip is shiny, and so on.
So why do you hate it? Just to be edgy? This is El Reg, not Physical Review B.
The point of the expression is of course to distinguish the capabilities of a new physical device from a "classical" one, which should be obvious to any El Reg reader. A short hand to say "quantum mechanical effects indeed shown to be used by D-Wave's quasi-quantum-annealing thing". Be glad that you don't get a LOHAN or PARIS crammed into the headline.
I dislike it because there is the implication that *only* this is quantum - that somehow, everything else isn't quantum. That incorrect dichotomy makes people reason incorrectly about what is going on - they begin to ascribe all sorts of magical properties to "quantum" gizmos, failing to take into account the fact that the world we live in is just as much driven by quantum mechanics as the new whizzygig that is being touted.
Even a few qubits on a chip is still better than the current "state of the art" requiring an MRI machine to read the bits stored in alcohol or chloroform etc.
Am I right in saying that their chip is limited by being a 2-D array of qubits so the physical separation becomes the limiting factor?
If so then an 8*8*8 3-D array of qubits with each layer having its own read/write lines and optics might provide stronger connectivity between the qubits.
Alternatively use cryptochrome C derived from nature as the quantum element and just run it at room temperature ?
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