Chen Jiyu, Werner Philipp
Department of Physics, University of Fribourg, 1700 Fribourg, Switzerland.
NPJ Comput Mater. 2025;11(1):127. doi: 10.1038/s41524-025-01619-0. Epub 2025 May 9.
Multidimensional coherent spectroscopy (MDCS) has been established in quantum chemistry as a powerful tool for studying the nonlinear response and nonequilibrium dynamics of molecular systems. More recently, the technique has also been applied to correlated electron materials, where the interplay of localized and itinerant states makes the interpretation of the spectra more challenging. Here we use the Keldysh contour representation of effective models and nonequilibrium dynamical mean field theory to systematically study the MDCS signals of prototypical correlated lattice systems. By analyzing the current induced by sequences of ultrashort laser pulses we demonstrate the usefulness of MDCS as a diagnostic tool for excitation pathways and coherent processes in correlated solids. We also show that this technique allows to extract detailed information on the nature and evolution of photo-excited nonequilibrium states.
多维相干光谱（MDCS）在量子化学中已成为研究分子系统非线性响应和非平衡动力学的有力工具。最近，该技术也被应用于关联电子材料，其中局域态和巡游态的相互作用使得光谱的解释更具挑战性。在这里，我们使用有效模型的凯尔迪什轮廓表示和非平衡动态平均场理论，系统地研究典型关联晶格系统的MDCS信号。通过分析超短激光脉冲序列所诱导的电流，我们证明了MDCS作为关联固体中激发路径和相干过程诊断工具的实用性。我们还表明，该技术能够提取有关光激发非平衡态的性质和演化的详细信息。
