Coherence generating power of unitary transformations via probabilistic average
Lin Zhang, Zhi-Hao Ma, Zhi-Hua Chen, and Shao-Ming Fei
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Submission date: 20. Aug. 2018
published in: Quantum information processing, 17 (2018) 7, art-no. 186
DOI number (of the published article): 10.1007/s11128-018-1928-4
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We study the ability of a quantum channel to generate quantum coherence when it applies to incoherent states. Based on probabilistic averages, we define a measure of such coherence generating power (CGP) for a generic quantum channel, based on the average coherence generated by the quantum channel acting on a uniform ensemble of incoherent states. Explicit analytical formula of the CGP for any unitary channels are presented in terms of subentropy. An upper bound for CGP of unital quantum channels has been also derived. Detailed examples are investigated.