Strongly bound excitons dominate the optical response in many van der Waals semiconductors, yet distinguishing between the different microscopic processes governing exciton dissociation remains challenging. Using time- and angle-resolved photoemission spectroscopy (TR-ARPES), we independently track exciton and band-edge carrier populations in bulk ReSe2 under resonant excitation. By studying the fluence dependence and polarization-controlled exciton density dependence of the exciton dissociation process, we distinguish between competing processes and identify exciton photoionization as the microscopic dissociation mechanism. These results establish a population-resolved strategy for resolving exciton-to-carrier conversion pathways in strongly excitonic materials.
@article{arxiv.2604.11906,
title = {Isolating Exciton Dissociation Pathways in ReSe$_{\text{2}}$},
author = {Bradley G. Guislain and Rysa Greenwood and Matteo Michiardi and Giorgio Levy and Sergey Zhdanovich and Jerry Icban Dadap and Sydney K. Y. Dufresne and Arthur K. Mills and Dario Armanno and Shawn Lapointe and Francesco Goto and Nicolas Gauthier and Fabio Boschini and Andrea Damascelli and Ziliang Ye and David J. Jones},
journal= {arXiv preprint arXiv:2604.11906},
year = {2026}
}