title: Local distinguishability of multipartite unitary operations.
abstract: We show that any two different unitary operations acting on an arbitrary multipartite quantum system can be perfectly distinguished by local operations and classical communication when a finite number of runs is allowed. Intuitively, this result indicates that the lost identity of a nonlocal unitary operation can be recovered locally. No entanglement between distant parties is required.
authors.affiliation: State Key Laboratory of Intelligent Technology and Systems, Department of Computer Science and Technology, Tsinghua University, Beijing, China, 100084. dry@tsinghua.edu.cn
authors.forename: Runyao
authors.initials: R
authors.lastname: Duan
authors.forename: Yuan
authors.initials: Y
authors.lastname: Feng
authors.forename: Mingsheng
authors.initials: M
authors.lastname: Ying