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arXiv · 1203.2251

Information gain versus coupling strength in quantum measurements

Xuanmin Zhu·Yuxiang Zhang·Quanhui Liu·Shengjun Wu
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Abstract

We investigate the relationship between the information gain and the interaction strength between the quantum system and the measuring device. A strategy is proposed to calculate the information gain of the measuring device as the coupling strength is a variable. For qubit systems, we prove that the information gain increases monotonically with the coupling strength. It is obtained that the information gain of the projective measurement along the x-direction reduces with the increasing of the measurement strength along the z-direction, and a complementarity of information gain in the measurements along those two directions is presented.

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Xuanmin Zhu, Yuxiang Zhang, Quanhui Liu, Shengjun Wu. 2012-05-05. Information gain versus coupling strength in quantum measurements. https://doi.org/10.1103/physreva.85.042330

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