发表机构
University of Michigan; Air Force Research Laboratory（密歇根大学; 空军研究实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究利用二维相干光谱分离光谱线宽中均匀和非均匀展宽贡献的问题，通过提供正交光谱切片减少简并性，以hBN封装的MoSe₂为例演示，相比线性沃伊特分析，能可靠分离贡献，降低参数相关性。
AI 中文摘要
在光谱线宽中分离均匀退相和非均匀展宽的贡献，对于将光谱与微观耗散和无序机制联系起来至关重要。对一维光谱（如光致发光）进行沃伊特拟合，会得到高度相关的高斯和洛伦兹宽度，因此无法独立确定任一宽度。我们定量表明，二维相干光谱（2DCS）通过提供对角和交叉对角的正交光谱切片，对均匀和非均匀展宽过程具有互补敏感性，从而减少了这种简并性。作为演示，我们在8K下测量了hBN封装的MoSe₂中的激子共振。联合不确定度加权拟合绘制了完整的χ²(σ,γ)景观以量化参数协方差。与线性沃伊特分析相比，2DCS产生更紧凑的置信区域并显著降低参数相关性，从而能够可靠地分离对激子线宽的贡献。
英文摘要
Separating homogeneous and inhomogeneous contributions to a spectral linewidth is essential for connecting optical spectra to microscopic dephasing and disorder. We quantitatively compare linewidth separation by one-dimensional Voigt analysis and two-dimensional coherent spectroscopy (2DCS). Using photoluminescence and 2DCS measurements of the same hBN-encapsulated monolayer MoSe2 sample, we construct uncertainty-weighted \c{hi}^2 landscapes for the Gaussian inhomogeneous width and Lorentzian homogeneous half-width. Although a Voigt profile accurately reproduces the photoluminescence spectrum, the two widths are strongly anticorrelated and therefore poorly determined independently. By contrast, joint fitting of diagonal and cross-diagonal 2DCS slices produces more compact confidence regions with reduced parameter correlation and elongation. These results quantitatively demonstrate the improved linewidth separation provided by 2DCS and illustrate the limitations of assigning homogeneous and inhomogeneous contributions from one-dimensional Voigt fits alone.
