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arXiv 1207.3307quant-ph
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变分方法的量子计量极限

Quantum Metrological Limits via a Variational Approach

B. M. Escher, L. Davidovich, N. Zagury, R. L. de Matos Filho

摘要:

物理参数估计中可达到的最小统计不确定度由量子费舍尔信息确定。它的计算噪声系统仍然是一个具有挑战性的问题。使用变分方法,我们提出了一个方程获得的量子费舍尔信息,它有一个明确的依赖于数学描述的噪声。应用该方法得到了相位扩散条件下相移估计的量子精度的解析界,表明估计不确定度不能小于噪声相关常数.

英文摘要:

The minimum achievable statistical uncertainty in the estimation of physical parameters is determined by the quantum Fisher information. Its computation for noisy systems is still a challenging problem. Using a variational approach, we present an equation for obtaining the quantum Fisher information, which has an explicit dependence on the mathematical description of the noise. This method is applied to obtain a useful analytical bound to the quantum precision in the estimation of phase-shifts under phase diffusion, which shows that the estimation uncertainty cannot be smaller than a noise-dependent constant.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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