Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warszawa, Poland.
Phys Rev Lett. 2023 Apr 21;130(16):160802. doi: 10.1103/PhysRevLett.130.160802.
Fisher information is a key notion in the whole field of quantum metrology. It allows for a direct quantification of the maximal achievable precision of the estimation of the parameters encoded in quantum states using the most general quantum measurement. It fails, however, to quantify the robustness of quantum estimation schemes against measurement imperfections, which are always present in any practical implementations. Here, we introduce a new concept of Fisher information measurement noise susceptibility that quantifies the potential loss of Fisher information due to small measurement disturbance. We derive an explicit formula for the quantity, and demonstrate its usefulness in the analysis of paradigmatic quantum estimation schemes, including interferometry and superresolution optical imaging.
Fisher 信息是整个量子计量学领域的一个关键概念。它允许直接量化使用最通用的量子测量对量子态中编码的参数进行估计的最大可实现精度。然而，它无法量化量子估计方案对测量误差的鲁棒性，因为在任何实际实现中总是存在测量误差。在这里，我们引入了 Fisher 信息测量噪声灵敏度的新概念，它量化了由于小的测量干扰而导致的 Fisher 信息的潜在损失。我们推导出了该量的显式公式，并在分析包括干涉测量和超分辨率光学成像在内的典型量子估计方案中展示了其有用性。
