A new coherence measure based on fidelity

作者:Liu, C. L.; Zhang, Da-Jian; Yu, Xiao-Dong; Ding, Qi-Ming; Liu, Longjiang*
来源:Quantum Information Processing, 2017, 16(8): 198.
DOI:10.1007/s11128-017-1650-7

摘要

Quantifying coherence is an essential endeavor for both quantum foundations and quantum technologies. In this paper, we put forward a quantitative measure of coherence by following the axiomatic definition of coherence measures introduced in Baumgratz et al. (PhysRev Lett 113: 140401, 2014). Ourmeasure is based on fidelity and analytically computable for arbitrary states of a qubit. As one of its applications, we show that our measure can be used to examine whether a pure qubit state can be transformed into another pure or mixed qubit state only by incoherent operations.