Quantum neural computer

[rohwerrj]

> >The characteristically 'quantum' properties of quantum computers,
> >such as the ability to run a superposition of programs simultaneously
> >on a single machine, arise only if the computer is a totally isolated
> >system; ie., it exchanges not a single quantum of energy with
> >its environment.  The brain fails this test pathetically.
> 
> 	This is not correct, as I understand it: a quantum

This *is* correct, which is why Deutch's work on quantum computers (1) draws
on Bennett's dissapationless "billiard ball computer" (2, 3).  The trouble
is that whether or not a perturbation collapses the wavefunction, which
is largely a philosophical undecidable (4), it does destroy quantum
phase information unless all quantum phase information is also known for
the perturbing system.

1. David Deutsch, "Quantum Theory, the Church-Turing principle, and the
universal quantum computer", Proc. Royal Society (London) A400, 97-117, (1985).

2. Charles. H. Bennett, IBM J. Res. Dev. 17, 525.

3. Charles. H. Bennett and Rolf Landauer, "The Fundamental Physical Limits
of Computation", Scientific American 253, no. 1, 38-53, (July 1985).

4. Hugh Everett, III, "'Relative State' Formulation of Quantum Mechanics",
Reviews of Modern Physics 29, 454-462, (1957).


Richard Rohwer
Dept. of Computer Science and Applied Mathematics
Aston University
Aston Triangle
Birmingham  B4 7ET
ENGLAND

Tel: (44 or 0) (21) 359-3611 x4688
FAX: (44 or 0) (21) 333-6215
rohwerrj at uk.ac.aston.cs