arXiv:quant-ph/0008113 · Physical Review A

Quantum Bayes rule

Rüdiger Schack, Todd A. Brun, Carlton M. Caves

Published Jun 13, 2001• 153 citations

Abstract

We state a quantum version of the Bayes rule for statistical inference and give a simple general derivation within the framework of generalized measurements. The rule can be applied to measurements on N copies of a system if the initial state of the N copies is exchangeable. As an illustration, we apply the rule to N qubits. Finally, we show that quantum state estimates derived via the principle of maximum entropy are fundamentally different from those obtained via the quantum Bayes rule.

DOI: 10.1103/physreva.64.014305

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