标题： 分析温稠密物质在虚时域中的X射线汤姆逊散射实验：理论模型和模拟 显示英文标题

标题： Analyzing X-ray Thomson scattering experiments of warm dense matter in the imaginary-time domain: theoretical models and simulations

摘要： 对温暖稠密物质（WDM）实验的严格诊断一直非常困难。 一种关键的方法是X射线汤姆逊散射（XRTS），但XRTS测量的解释通常基于包含各种近似的理论模型。 最近，Dornheim等人[arXiv:2206.12805]提出了一种新的XRTS实验温度诊断框架，该框架基于虚时关联函数（ITCF）。 一方面，从频率域转换到虚时域可以直接获得许多物理性质，这有助于在没有任何模型或近似的情况下提取任意复杂材料的温度。 另一方面，动态量子多体理论中的大部分理论工作都集中在频率域，据我们所知，物理性质在ITCF中的表现仍然理解得不够充分。 在本工作中，我们旨在通过在虚时路径积分框架下引入一个简单、半解析的两体关联虚时依赖模型来改变这种不令人满意的情况。 作为实际例子，我们将新模型与均匀电子气体的ITCF的大量第一性原理路径积分蒙特卡罗结果进行比较，并在广泛的波数、密度和温度范围内发现良好的一致性。 显示英文摘要

摘要： The rigorous diagnostics of experiments with warm dense matter (WDM) is notoriously difficult. A key method is given by X-ray Thomson scattering (XRTS), but the interpretation of XRTS measurements is usually based on theoretical models that entail various approximations. Recently, Dornheim et al. [arXiv:2206.12805] have introduced a new framework for temperature diagnostics of XRTS experiments that is based on imaginary-time correlation functions (ITCF). On the one hand, switching from the frequency- to the imaginary-time domain gives one direct access to a number of physical properties, which facilitates the extraction of the temperature of arbitrarily complex materials without any models or approximations. On the other hand, the bulk of theoretical works in dynamic quantum many-body theory is devoted to the frequency-domain, and, to our knowledge, the manifestation of physics properties within the ITCF remains poorly understood. In the present work, we aim to change this unsatisfactory situation by introducing a simple, semi-analytical model for the imaginary-time dependence of two-body correlations within the framework of imaginary-time path integrals. As a practical example, we compare our new model to extensive ab initio path integral Monte Carlo results for the ITCF of a uniform electron gas, and find excellent agreement over a broad range of wave numbers, densities, and temperatures.