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Derivation of the quantum probability law from minimal non-demolition measurement. (English) Zbl 1121.81011
Summary: One more derivation of the quantum probability rule is presented in order to shed more light on the versatile aspects of this fundamental law. It is shown that the change of state in minimal quantum non-demolition measurement, also known as ideal measurement, implies the probability law in a simple way. Namely, the very requirement of minimal change of state, put in proper mathematical form, gives the well-known Lüders formula, which contains the probability rule.
MSC:
81P15Quantum measurement theory
81P05General and philosophical topics in quantum theory