Gefen T, Rotem A, Retzker A
Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem, 91904, Givat Ram, Israel.
Nat Commun. 2019 Nov 1;10(1):4992. doi: 10.1038/s41467-019-12817-y.
The field of quantum sensing explores the use of quantum phenomena to measure a broad range of physical quantities, of both static and time-dependent types. While for static signals the main figure of merit is sensitivity, for time dependent signals it is spectral resolution, i.e. the ability to resolve two different frequencies. Here we study this problem, and develop new superresolution methods that rely on quantum features. We first formulate a general criterion for superresolution in quantum problems. Inspired by this, we show that quantum detectors can resolve two frequencies from incoherent segments of the signal, irrespective of their separation, in contrast to what is known about classical detection schemes. The main idea behind these methods is to overcome the vanishing distinguishability in resolution problems by nullifying the projection noise.
量子传感领域探索利用量子现象来测量各种物理量，包括静态和随时间变化的类型。对于静态信号，主要的品质因数是灵敏度；对于随时间变化的信号，则是光谱分辨率，即分辨两个不同频率的能力。在此，我们研究这个问题，并开发基于量子特性的新超分辨率方法。我们首先为量子问题中的超分辨率制定了一个通用标准。受此启发，我们表明量子探测器能够从信号的非相干段分辨出两个频率，而不论它们的间隔如何，这与经典检测方案的已知情况形成对比。这些方法背后的主要思想是通过消除投影噪声来克服分辨率问题中逐渐消失的可区分性。
