Measuring unrecorded measurement
Department of Physics, Technion-Israel Institute of Technology - Haifa 32000, Israel
Received: 27 April 2016
Accepted: 10 August 2016
Projective (von Neumann) measurement of an operator (i.e., a dynamical variable) selected from a prescribed set of operators is termed unrecorded measurement (URM) when both the selected operator and the measurement outcome are unknown, i.e., “lost”. Within classical physics a URM is completely inconsequential: the state is unaffected by measurement. Within quantum physics a measurement leaves a mark. The present study provides protocols that allow the retrieval of some of the data lost in a URM. The study is shown as supportive of viewing quantum measurement as made up of both classical-like and pure quantum components.
PACS: 03.65.Ta – Foundations of quantum mechanics; measurement theory / 03.67.Hk – Quantum communication
© EPLA, 2016