1993/04/01 by Fritz Haake, Marek Żukowski · 1 citation
Physics and Astronomy · Computer Science · #Quantum Mechanics and Applications #Spectroscopy and Quantum Chemical Studies #Quantum Information and Cryptography
paper · doi:10.1103/physreva.47.2506
openalex publication_date 1993/04/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We describe the measurement process for a model system whose Schr"odinger equation yields to explicit solution. Any device for an effectively irreversible measurement must not just be a ``meter'' with a single degree of freedom; it must also contain a ``heat bath'' with many degrees of freedom. Such a bath may cause an effectively instantaneous decay of quantum coherences between macroscopically distinct meter readings, i.e., impart practically classical behavior to the meter. In turn, such a meter can be read without thereby suffering back reactions. We establish the limits in which a meter reading is uniquely related, with reasonable certainty, to a definite eigenvalue of the measured observable.