title: Simple understanding of quantum weak values.
abstract: In this work we revisit the important and controversial concept of quantum weak values, aiming to provide a simplified understanding to its associated physics and the origin of anomaly. Taking the Stern-Gerlach setup as a working system, we base our analysis on an exact treatment in terms of quantum Bayesian approach. We also make particular connection with a very recent work, where the anomaly of the weak values was claimed from the pure statistics in association with "disturbance" and "post-selection", rather than the unique quantum nature. Our analysis resolves the related controversies through a clear and quantitative way.
authors.affiliation: Center for Advanced Quantum Studies and Department of Physics, Beijing Normal University, Beijing 100875, China.
authors.forename: Lupei
authors.initials: L
authors.lastname: Qin
authors.affiliation: Department of Physics, Tianjin University, Tianjin 300072, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Feng
authors.affiliation: Center for Advanced Quantum Studies and Department of Physics, Beijing Normal University, Beijing 100875, China.
authors.forename: Xin-Qi
authors.initials: XQ
authors.lastname: Li
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