Recovering Classical Dynamics from Coupled Quantum Systems Through Continuous Measurement
نویسندگان
چکیده
We study the role of continuous measurement in the quantum to classical transition for a system with coupled internal ~spin! and external ~motional! degrees of freedom. Even when the measured motional degree of freedom can be treated classically, entanglement between spin and motion causes strong measurement back action on the quantum spin subsystem so that classical trajectories are not recovered in this mixed quantumclassical regime. The measurement can extract localized quantum trajectories that behave classically only when the internal action also becomes large relative to \.
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