Revisiting weak measurement in light of thermodynamics

Daiki Ueda; Hikaru Ohta; Sumito Yokoo

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arXiv · 1910.12189

Revisiting weak measurement in light of thermodynamics

Daiki Ueda·Hikaru Ohta·Sumito Yokoo

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Abstract

We investigate a weak measurement described by a von Neumann type interaction $\hat{A}\otimes \hat{p}^2$, where $\hat{A}$ is a system observable and $\hat{p}^2$ is a measurement pointer observable. We consider the weak measurement in terms of thermodynamics by adopting a mixed Gaussian state as a quantum state of the measurement pointer. We show that Maxwell's demon appears as a measure who carries out post-selections. It is found that, even if the demon only knows the weak value, a difference in the von Neumann entropy between the initial and final system can be the QC mutual information contents, which is the maximum amount of obtainable information by a measurement. Besides, our study indicates that a temperature of the system described by this interaction is amplified by weak value amplification. In addition, we show that this demon can be realized in an atomic system.

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cond-mat.stat-mech cond-mat.quant-gas quant-ph

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Daiki Ueda, Hikaru Ohta, Sumito Yokoo. 2019-10-27. Revisiting weak measurement in light of thermodynamics. https://arxiv.org/abs/1910.12189

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