论文标题
精确估计偶极发射器的方向和摆动的量子限制
Quantum limits for precisely estimating the orientation and wobble of dipole emitters
论文作者
论文摘要
精确测量分子取向是了解分子如何在软物质中组织和相互作用的关键，但是测量精度的最大理论极限尚未量化。我们使用量子估计理论和Fisher信息（QFI）来得出基于估计旋转固定分子方向的精度的基本结合。尽管显微镜的直接成像达到了量子结合，但它与广场成像不兼容，因此我们提出了一个干涉成像系统，该系统也可以达到QFI限制的测量精度。将我们的分析扩展到旋转扩散的分子，我们得出了使二阶偶极取向矩的子集以量子限制的精度测量的条件。有趣的是，我们发现没有现有的技术可以用QFI限制的精度同时测量所有第二瞬间。精确测量分子的平均方向与摇摆之间存在基本的权衡。该理论分析提供了优化对方向敏感成像系统设计的关键见解。
Precisely measuring molecular orientation is key to understanding how molecules organize and interact in soft matter, but the maximum theoretical limit of measurement precision has yet to be quantified. We use quantum estimation theory and Fisher information (QFI) to derive a fundamental bound on the precision of estimating the orientations of rotationally fixed molecules. While direct imaging of the microscope pupil achieves the quantum bound, it is not compatible with widefield imaging, so we propose an interferometric imaging system that also achieves QFI-limited measurement precision. Extending our analysis to rotationally diffusing molecules, we derive conditions that enable a subset of second-order dipole orientation moments to be measured with quantum-limited precision. Interestingly, we find that no existing techniques can measure all second moments simultaneously with QFI-limited precision; there exists a fundamental trade-off between precisely measuring the mean orientation of a molecule versus its wobble. This theoretical analysis provides crucial insight for optimizing the design of orientation-sensitive imaging systems.
