基于低维光谱表示的NV电荷态贡献几何估计
Geometric estimation of NV charge-state contributions from a low-dimensional spectral representation
- School of Engineering, Institute of Science Tokyo（东京科学大学工学院）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本文提出一种几何方法，通过低维光谱表示和零声子线校准，从光致发光光谱中估计金刚石NV中心的电荷态贡献，实验验证精度高且抗噪性强。
AI中文摘要：
金刚石中的氮-空位（NV）中心以中性（NV0）和带负电（NV-）两种状态存在，量化它们各自的光致发光（PL）贡献对于基于电荷态的测量至关重要。现有方法要么需要额外的实验控制，要么可能受限于物理可辨识性不足。本文提出了一种几何方法，用于从不同激发强度下获取的PL光谱中确定NV电荷态贡献。每个光谱通过宽带光谱加权映射到低维空间，其中相对NV0和NV-贡献的变化描绘出一条一维轨迹。来自两个光谱的零声子线（ZPL）信息对该轨迹进行物理校准，从而通过几何投影确定NV-PL贡献。对两块体单晶金刚石样品的测量得到的NV-贡献与使用独立双激发参考光谱方法获得的结果高度一致，均方根误差分别为1.11和0.31个百分点。在加性光谱噪声下，所提方法的变异比仅使用ZPL的方法低一个数量级以上。Fisher信息分析进一步表明，三维CIE XYZ表示保留了全光谱中关于NV-贡献约81%的信息。这些结果建立了一种物理校准的低维光谱估计方法，兼具降低的实验开销和稳健的参数估计，并为受少数物理自由度控制的光谱传感提供了通用框架。
英文摘要：
Nitrogen-vacancy (NV) centers in diamond exist in neutral (NV0) and negatively charged (NV-) states, and quantifying their respective photoluminescence (PL) contributions is important for charge-state-based measurements. Existing methods either require additional experimental control or may suffer from limited physical identifiability. Here, we introduce a geometric method for determining NV charge-state contributions from PL spectra acquired at different excitation intensities. Each spectrum is mapped into a low-dimensional space through broadband spectral weighting, where changes in the relative NV0 and NV- contributions trace a one-dimensional trajectory. Zero-phonon-line (ZPL) information from two spectra physically calibrates this trajectory, enabling the NV-PL contribution to be determined by geometric projection. Measurements on two bulk single-crystal diamond samples yielded NV- contributions in close agreement with those obtained using an independent dual-excitation reference-spectrum method, with root-mean-square errors of 1.11 and 0.31 percentage points. Under additive spectral noise, the proposed method exhibited more than an order of magnitude less variation than a ZPL-only method. Fisher-information analysis further showed that the three-dimensional CIE XYZ representation retained approximately 81% of the information about the NV- contribution available in the full spectrum. These results establish a physically calibrated approach to low-dimensional spectral estimation that combines reduced experimental overhead with robust parameter estimation and provides a general framework for spectral sensing governed by a small number of physical degrees of freedom.
