There are lots of different ways to build a quantum computer, so you might get conflicting answers about the materials and signaling mechanisms. But what they have in common is that they are probabilistic, and there are very few algorithms that take advantage of this to speed things up instead of just adding noise. Shor's algorithm for factoring numbers and Grover's search algorithm work by constructive and destructive interference of the wavefunctions of entangled particles, amplifying the probabilities of the right answers. http://twistedoakstudios.com/blog/Post2644_grovers-quantum-s... http://algassert.com/post/1718