Covariant feedback Control of arbitrary qudit state against Depolarizing Noise is impossible
Quantum Physics
2008-11-21 v1
Abstract
In this paper, we prove that it is impossible to construct a convariant quantum feedback control instruments which aim to correct the channel noise imposed on an unknown qubit. The proof is based on the searching for the optimal quantum control protocol and it turns out there exist no better %\textit{Complete Positive Trace %Preserving}(CPTP) maps complete positive and covariant quantum operations which provide a higher fidelity than the trivial Identity operators. The generalization of the investigation to bipartite entangled pure state is also included.
Cite
@article{arxiv.0811.3254,
title = {Covariant feedback Control of arbitrary qudit state against Depolarizing Noise is impossible},
author = {ShengLi Zhang and XuBo Zou and Chuanfeng Li and ChenHui Jin and GuangCan Guo},
journal= {arXiv preprint arXiv:0811.3254},
year = {2008}
}
Comments
submitted for publication on June 29, 2008