多粒子干涉与量子纠错
摘要
借助经典纠错码理论所提供的洞见，讨论了多粒子干涉的概念。这引出了对量子通信信道或量子计算机中纠错的讨论。给出了量子体制下的纠错方法，并评估了其局限性。若将 K 个量子信息比特用 n 个量子比特编码，则量子信道可从 x 个量子比特的任意退相干中恢复，其中 K/n 可大于 1-2 H(2x/n)，但必须小于 1-2 H(x/n)。这意味着退相干随所需计算资源仅多项式增加而指数式减少。因此，在物理上现实的退相干水平下，量子计算可以做到无错误。这些方法也允许将量子通信与噪声和窃听隔离（量子私密放大）。
引用
@article{arxiv.quant-ph/9601029,
title = {Multiple Particle Interference and Quantum Error Correction},
author = {Andrew Steane},
journal= {arXiv preprint arXiv:quant-ph/9601029},
year = {2009}
}
备注
Submitted to Proc. Roy. Soc. Lond. A. in November 1995, accepted May 1996. 39 pages, 6 figures. This is now the final version. The changes are some added references, changed final figure, and a more precise use of the word `decoherence'. I would like to propose the word `defection' for a general unknown error of a single qubit (rotation and/or entanglement). It is useful because it captures the nature of the error process, and has a verb form `to defect'. Random unitary changes (rotations) of a qubit are caused by defects in the quantum computer; to entangle randomly with the environment is to form a treacherous alliance with an enemy of successful quantum