ancilla

To realize the scheme we made use Bell analyzer, Hadamard gate transformation, ancilla electron and electronic polarizing beam splitters.

该方案主要利用电荷探测器、Bell分析器、Hadamard门变换、辅助电子及电子偏振光束分离器。

Space-like separated two users share a pair of non-maximally entangled particles. To enhance the remote entanglement, each of the two users will introduce an ancilla.

类空分离的两用户分享一对非最大纠缠粒子对，两用户分别引入辅助粒子。

Our scheme has some outstanding features: First, the two clones work without the need of an ancilla this is called economical cloning thus it is likely to be much less sensitive to noise and decoherence.

我们的方案有如下优点：1.这两个克隆不需要辅助粒子，因此称为经济型克隆并且对环境噪声不敏感。

It entangles and then disentangles the ancilla with the carrier using two controlled-not gates, by which not only the dishonest participant but the eavesdropper outside can elicit about half of the key.

该攻击利用两次控制非门操作使得附加粒子与载体纠缠再解纠缠，从而使得不仅内部参与者甚至外部窃听者都可以获得一半密钥。