Adaptive Quantum Metrology under General Markovian Noise
Adaptive Quantum Metrology under General Markovian Noise
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DOI：
10.1103/physrevx.7.041009
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发表时间：
2017-10-16
影响因子：
12.5
通讯作者：
Sekatski, Pavel
中科院分区：
文献类型：
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作者：
Demkowicz-Dobrzanski, Rafal;Czajkowski, Jan;Sekatski, Pavel
我们考虑了一般的马尔可夫噪声下的酉参数估计模型，其中被估计的参数与动力学的哈密顿部分有关。在没有噪声的情况下，可以用1/T的精度尺度估计么正参数，其中T是总探测时间。我们给出了一个仅涉及量子主方程中出现的算符的简单代数条件，这意味着在最一般的自适应量子估计策略下，精度至多为1/根T标度。我们还讨论了在上述代数条件不满足的情况下，为了恢复1/T精度标度，类量子纠错协议必须满足的条件。此外，我们应用所开发的方法来理解考虑多体效应的原子干涉测量中的基本精度极限，为了解非线性计量模型的性能提供了新的线索。
We consider a general model of unitary parameter estimation in the presence of Markovian noise, where the parameter to be estimated is associated with the Hamiltonian part of the dynamics. In the absence of noise, the unitary parameter can be estimated with precision scaling as 1/T, where T is the total probing time. We provide a simple algebraic condition involving solely the operators appearing in the quantum master equation, implying, at most, 1/root T scaling of precision under the most general adaptive quantum estimation strategies. We also discuss the requirements a quantum error-correction-like protocol must satisfy in order to regain the 1/T precision scaling in case the above-mentioned algebraic condition is not satisfied. Furthermore, we apply the methods developed to understand fundamental precision limits in atomic interferometry with many-body effects taken into account, shedding new light on the performance of nonlinear metrological models.