New Limits on Fault-Tolerant Quantum Computation
Quantum Physics
2007-05-23 v2
Abstract
We show that quantum circuits cannot be made fault-tolerant against a depolarizing noise level of approximately 45%, thereby improving on a previous bound of 50% (due to Razborov). Our precise quantum circuit model enables perfect gates from the Clifford group (CNOT, Hadamard, S, X, Y, Z) and arbitrary additional one-qubit gates that are subject to that much depolarizing noise. We prove that this set of gates cannot be universal for arbitrary (even classical) computation, from which the upper bound on the noise threshold for fault-tolerant quantum computation follows.
Cite
@article{arxiv.quant-ph/0604141,
title = {New Limits on Fault-Tolerant Quantum Computation},
author = {Harry Buhrman and Richard Cleve and Monique Laurent and Noah Linden and Alexander Schrijver and Falk Unger},
journal= {arXiv preprint arXiv:quant-ph/0604141},
year = {2007}
}
Comments
references and typos corrected, 18 pages