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Phase-covariant quantum cloning of qudits

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

We study the phase-covariant quantum cloning machine for qudits, i.e. the input states in d-level quantum system have complex coefficients with arbitrary phase but constant module. A cloning unitary transformation is proposed. After optimizing the fidelity between input state and single qudit reduced density opertor of output state, we obtain the optimal fidelity for 1 to 2 phase-covariant quantum cloning of qudits and the corresponding cloning transformation.

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Heng Fan, Hiroshi Imai, Keiji Matsumoto, Xiang-Bin Wang. 2002-12-03. Phase-covariant quantum cloning of qudits. https://doi.org/10.1103/physreva.67.022317

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