10 years ago, we did
a real quantum computer with nuclear spins on a pretty molecule with spins and 7 qbits with a classic magnetic resonance apparatus on spins of atomic nuclei !!
So far this is the
max number of qbit really functional!
Nature 414, 883 (2001) and read:
http://www.nature.com/nature/journal/v4 ... 4883a.html
http://www.utinam.cnrs.fr/Ordinateur-qu ... -a-base-de
http://en.wikipedia.org/wiki/Nuclear_magnetic_resonance
http://xstructure.inr.ac.ru/x-bin/revth ... 521&skip=0
http://en.wikipedia.org/wiki/Quantum_computer
http://fr.wikipedia.org/wiki/Calculateur_quantique
If we improve the signal on noise, we can make quantum computers on much larger molecules.
In this case we manipulate each spin perfectly of each molecule which individually keeps its coherence and the only problem is the signal on noise.
Any microscopic phenomenon, a molecule, etc. can make a quantum computer but the difficulty is to manipulate each qbit element and the interactions as desired without losing coherence.
With a large number of qbit, the coherence will be very difficult to maintain, worse difficulty than the signal on noise in magnetic resonance.
We manipulate the orientation of the magnetic moments of the nuclei with photons of radio waves !!
Finally for: Researchers get trapped photons to act like massive particles
http://arstechnica.com/science/news/201 ... ticles.ars
the mass of these photons is that of the electron clouds of the coloring molecules excited by the photons so strongly that they are coherent electrons mixed quantitatively with the photons trapped in these molecules by their electrons !!
They're not entirely sure what to do with it at the moment,
and the quantum computer is far away with this experiment, much further than with the magnetic resonance of spins !!