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arXiv 1504.03214quant-ph
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相干平均

Coherent Averaging

Julien M. E. Fraïsse, Daniel Braun

AI总结:

本文研究相干平均方案在量子参数测量中实现海森堡极限灵敏度的能力,通过解析与数值方法揭示了灵敏度随探针数N的标度及其对初态、相互作用强度等条件的依赖。

摘要:

我们详细研究了一种最近提出的“相干平均方案”,考察其在测量不同参数时实现海森堡极限灵敏度的有效性。在该方案中,处于乘积态的N个量子探针与一条量子总线相互作用。与经典平均中直接测量探针后再取平均不同,该方案测量量子总线或整个系统,并尝试从这些测量结果中估计参数。结合微扰理论的解析结果、一个精确可解的去相位模型以及数值模拟,我们详细描绘了最佳可实现灵敏度随N的标度关系,以及其对初始状态、相互作用强度、被测系统部分和所研究参数的依赖关系。

英文摘要:

We investigate in detail a recently introduced "coherent averaging scheme" in terms of its usefulness for achieving Heisenberg limited sensitivity in the measurement of different parameters. In the scheme, $N$ quantum probes in a product state interact with a quantum bus. Instead of measuring the probes directly and then averaging as in classical averaging, one measures the quantum bus or the entire system and tries to estimate the parameters from these measurement results. Combining analytical results from perturbation theory and an exactly solvable dephasing model with numerical simulations, we draw a detailed picture of the scaling of the best achievable sensitivity with $N$, the dependence on the initial state, the interaction strength, the part of the system measured, and the parameter under investigation.

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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