Experimental demonstration of entanglement-enabled universal quantum cloning in a circuit
Experimental demonstration of entanglement-enabled universal quantum cloning in a circuit
复制标题
电路中启用纠缠的通用量子克隆的实验演示
DOI：
10.1038/s41534-021-00375-5
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发表时间：
2021
影响因子：
7.6
通讯作者：
Shi-Biao Zheng
中科院分区：
文献类型：
--
作者：
Zhen-Biao Yang;Pei-Rong Han;Xin-Jie Huang;Wen Ning;Hekang Li;Kai Xu;Dongning Zheng;Heng Fan;Shi-Biao Zheng
不可克隆定理禁止对未知量子态进行完美克隆。通用量子克隆机（UQCM）能够以最佳保真度产生任意输入量子比特的两个副本，是量子信息处理领域的基础研究和应用。这是通过在输入量子位和复制量子位之间精心定制的非经典相关性来实现的，这将UQCM与经典对口物区分开来，但其实验证明仍然缺乏。我们在超导电路中实现了UQCM，并研究了这些相关性。测量到的纠缠很好地符合我们的理论预测，即它们独立于输入状态，因此构成了以前未被揭示的UQCM的普遍量子行为。我们实验的另一个特点是实现了确定性和个体克隆，而不是之前演示的UQCMs，它们要么是概率的，要么不构成单个量子位的真正克隆。
No-cloning theorem forbids perfect cloning of an unknown quantum state. A universal quantum cloning machine (UQCM), capable of producing two copies of any input qubit with the optimal fidelity, is of fundamental interest and has applications in quantum information processing. This is enabled by delicately tailored nonclassical correlations between the input qubit and the copying qubits, which distinguish the UQCM from a classical counterpart, but whose experimental demonstrations are still lacking. We here implement the UQCM in a superconducting circuit and investigate these correlations. The measured entanglements well agree with our theoretical prediction that they are independent of the input state and thus constitute a universal quantum behavior of the UQCM that was not previously revealed. Another feature of our experiment is the realization of deterministic and individual cloning, in contrast to previously demonstrated UQCMs, which either were probabilistic or did not constitute true cloning of individual qubits.