Decoherence-free quantum information processing with four-photon entangled states
Decoherence-free quantum information processing with four-photon entangled states
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DOI：
10.1103/physrevlett.92.107901
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发表时间：
2004-03-12
影响因子：
8.6
通讯作者：
Weinfurter, H
中科院分区：
文献类型：
--
作者：
Bourennane, M;Eibl, M;Weinfurter, H
无消相干态保护量子信息不受集体噪声的影响，集体噪声是当前量子通信和计算实现中消相干的主要原因。在这里，我们证明了自发参数下转换可以用来产生四光子态，从而能够在无消相干的子空间中对一个量子比特进行编码。编码后的量子比特的量子状态层析成像验证了其对噪声的免疫力。我们表明，仅通过对四个光子的局域测量就可以区分编码量子比特的特定状态。
Decoherence-free states protect quantum information from collective noise, the predominant cause of decoherence in current implementations of quantum communication and computation. Here we demonstrate that spontaneous parametric down conversion can be used to generate four-photon states which enable the encoding of one qubit in a decoherence-free subspace. The immunity against noise is verified by quantum state tomography of the encoded qubit. We show that particular states of the encoded qubit can be distinguished by local measurements on the four photons only.