NANOSYSTEMS: PHYSICS, CHEMISTRY, MATHEMATICS, 2013, 4 (5), P. 635–647
REDUCED CONDITIONAL DYNAMIC OF QUANTUM SYSTEM UNDER INDIRECT QUANTUM MEASUREMENT
A. I. Trifanov – Saint Petersburg National Research University of Information Technologies, Mechanics and Optics, 197101, 49 Kronverksky, Saint Petersburg, Russia; alextrifanov@gmail.com
G. P. Miroshnichenko – Saint Petersburg National Research University of Information Technologies, Mechanics and Optics, 197101, 49 Kronverksky, Saint Petersburg, Russia; gpmirosh@gmail.com
In this report, we study the reduced conditional dynamics of a quantum system in the case of indirect quantum measurement. The detector’s microscopic part (pointer) interacts with the measured system (target) and the environment, which results in a nonunitary interaction between target and pointer. The quantum state evolution conditioned by the measurement result is under investigation. Particularly, we are interested in explicit analytical expressions for the conditional evolution superoperators and basic information characteristics of this measurement process, which is applied to the cavity mode photodetection problem.
Keywords: indirect quantum measurements, conditional evolution, photodetection problem, rotating wave approximation, quantum entropy.
PACS 42.50.Ar, 42.50.Lc, 42.50.Pq