Vidiš - svaki sistem je i kvantni sistem i može biti qubit... . Imaš jedan proton i oko njega se vrti elektron i eto ti jednog kvantnog stanja sa dva spinska stanja - kubita... Pa to ne čini flašu vode nekim izuzetno moćnim kvantnim kompjuterom... Ali da bi se mogle obavljati kvantna računanja nije dovoljno da ima određen broj kubita koji se ponašaju nezavisno jedan od drugog - već ti kubiti moraju biti koherentni - njihova stanja moraju biti dio jednog sistema... Mjerenjem stanja jednog od tih kubita ti moraš rušiti dio stanja kvantne funkcije svih kubita... Da bi se to postiglo moraju se sniziti i temperature i eliminisati svi spoljni uticaji (što oni očigledno pokušavaju da urade) i sa povećanjem kubita postaje progresivno sve teže i teže...
Evo i da citiram iz ovih članaka - pošto su neki očigledno ljeni da čitaju:
2. A Physics Breakthrough?: Achieving 16 coherent superconducting quantum bits (malo stara informacija - sad tvrde mnogo više) would be quite a breakthrough. Physicists working on superconducting qubits have not been able to achieve more than two coherent quantum bits in the lab. In the absence of evidence from D-Wave that their 16 qubits are coherent, scientists are understandably skeptical. If D-Wave’s qubits are not coherent, as many scientists suspect, their computer would be classical, not quantum.
To whack through really big computations that would take an infinite amount of time on a classical computer, he says, D-Wave’s chip also has to maintain a kind of delicate synchrony between the individual qubits called coherence. But it’s possible that D-Wave’s qubits lose coherence very quickly to act more or less independently but nonetheless tunnel to their collective ground state. And in that case, the computer can’t hope to be any more efficient than a regular one, van Dam says.
Question about how they would prove that their system is quantum is a good one, since it does not have an obvious answer. For a traditional gate-based quantum computer, one would want to see coherent control of the qubits (called Rabi oscillations) and state tomography to demonstrate entanglement of qubits. D-Wave is attempting something very different, called an adiabatic quantum computer. The same tests don't apply here. But, it would be nice for them to demonstrate a feature of their system, like an avoided crossing between coupled qubits, to show that it is at least quantum-like.
They could also just solve a problem from a 3rd party in a time which is much faster than is possible which a conventional computer.
Read more:
http://news.cnet.com/Start-up-...8_3-6159152.html#ixzz1OVUXoHVi
http://blogs.forbes.com/alexkn...n-on-d-waves-quantum-computer/
Zaključak je da ovo definitivno nije onakav kvantni kompjuter kako su ga pioniri kvantnih kompjutera zamislili da bude - a sad da li je sposoban da radi iste stvari - saznaćemo vremenom. Kada počne neke probleme brže rešava od običnih kompjutera - znaćemo da su nešto postigli i čak i ako se i pokaže da je to slijepi put u kvantno kompjuterstvo njihov rad će biti mnogo značajniji... Do tad je to uglavnom prazna priča...
[Ovu poruku je menjao Stijak dana 06.06.2011. u 17:06 GMT+1]