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Balance between information gain and reversibility in weak measurement
We derive a tight bound between the quality of estimating a quantum state by
measurement and the success probability of undoing the measurement in arbitrary
dimensional systems, which completely describes the tradeoff relation between
the information gain and reversibility. In this formulation, it is clearly
shown that the information extracted from a weak measurement is erased through
the reversing process. Our result broadens the information-theoretic
perspective on quantum measurement as well as provides a standard tool to
characterize weak measurements and reversals.Comment: 5 pages, final versio
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