Automatic Feynman diagram generation for nonlinear optical spectroscopies and application to fifth-order spectroscopy with pulse overlaps

Perturbative nonlinear optical spectroscopies are powerful methods to understand the dynamics of excitonic and other condensed phase systems. Feynman diagrams have long provided essential tool interpret experimental spectra organize calculation for model When pulses strictly time ordered, only a small number contribute, but in many experiments pulse-overlap effects important interpreting results. overlap, contributing can increase rapidly, especially with higher order spectroscopies, human error is likely when attempting write down all diagrams. We present an automated Diagram Generator (DG) that generates needed calculate any $n^{\text{th}}$-order spectroscopic signal. characterize perturbative by their associated phase-discrimination condition as well intervals where pulse amplitudes nonzero. Although DG be used automate impulsive calculations, its greatest strength lies automating finite calculations overlaps important. consider third-order transient absorption spectroscopy fifth-order exciton-exciton interaction 2D (EEI2D) spectroscopy, which respectively described 6 or 7 limit 16 240 diagrams, respectively, overlap. The allows users automatically include relevant at relatively low computational cost, since extra generated inter-pulse delays they relevant. For EEI2D we show including overlap