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论文类型：期刊论文

发表时间：2020-01-01

发表刊物：QUANTUM INFORMATION PROCESSING

收录刊物：EI、SCIE

卷号：19

期号：1

ISSN号：1570-0755

关键字：Quantum coherence; Quantum Fisher information; Superposition

摘要：Quantum Fisher information as an important quantity in quantum metrology determines the upper bound of the measurement accuracy. It is shown that the quantum feature such as entanglement can improve quantum Fisher information in some cases. Here we study how quantum coherence affects the quantum Fisher information from a general point of view. We find out that the bounds induced by the superposed states can well restrict the quantum Fisher information in a general parameter estimation scheme. As applications, we demonstrate these bounds by a parameter estimation process with the superposition input state undergoing different quantum channels.