Is FaultTolerant Quantum Computation Really Possible?
Abstract
The socalled "threshold" theorem says that, once the error rate per qubit per gate is below a certain value, indefinitely long quantum computation becomes feasible, even if all of the qubits involved are subject to relaxation processes, and all the manipulations with qubits are not exact. The purpose of this article, intended for physicists, is to outline the ideas of quantum error correction and to take a look at the proposed technical instruction for faulttolerant quantum computation. It seems that the mathematics behind the threshold theorem is somewhat detached from the physical reality, and that some ideal elements are always present in the construction. This raises serious doubts about the possibility of large scale quantum computations, even as a matter of principle.
 Publication:

arXiv eprints
 Pub Date:
 October 2006
 arXiv:
 arXiv:quantph/0610117
 Bibcode:
 2006quant.ph.10117D
 Keywords:

 Quantum Physics;
 Condensed Matter  Other;
 Condensed Matter  Strongly Correlated Electrons;
 Physics  Atomic Physics
 EPrint:
 Based on a talk given at the Future Trends in Microelectronics workshop, Crete, June 2006. 8 pages, 1 figure