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A universal cloner allowing the input to be arbitrary states in symmetric subspace

Heng Fan·Keiji Matsumoto·Xiang-Bin Wang·Hiroshi Imai·Miki Wadati
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Abstract

A generalized universal quantum cloning machine is proposed which allows the input to be arbitrary states in symmetric subspace. And it reduces to the universal quantum cloning machine (UQCM) if the input are identical pure states. The generalized cloner is optimal in the sense we compare the input and output reduced density operators at a single qubit. The result for qubits is extended to arbitrary-dimensional states.

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Heng Fan, Keiji Matsumoto, Xiang-Bin Wang, Hiroshi Imai, Miki Wadati. 2001-08-13. A universal cloner allowing the input to be arbitrary states in symmetric subspace. https://arxiv.org/abs/quant-ph/0107113

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