title: Identification and distance measures of measurement apparatus.
abstract: We propose simple schemes that can perfectly identify projective measurement apparatuses secretly chosen from a finite set. Entanglement is used in these schemes both to make possible the perfect identification and to improve the efficiency significantly. Based on these results, a brief discussion on the problem of how to appropriately define distance measures of measurements is also provided.
authors.affiliation: State Key Laboratory of Intelligent Technology and Systems, Department of Computer Science and Technology, Tsinghua University, Beijing 100084, China. jizhengfeng98@mails.tsinghua.edu.cn
authors.forename: Zhengfeng
authors.initials: Z
authors.lastname: Ji
authors.forename: Yuan
authors.initials: Y
authors.lastname: Feng
authors.forename: Runyao
authors.initials: R
authors.lastname: Duan
authors.forename: Mingsheng
authors.initials: M
authors.lastname: Ying