Multidimensional coherent spectroscopy directly unravels multiply excited states that overlap in a linear spectrum. We report multidimensional coherent optical photocurrent spectroscopy in a semiconductor polariton diode and explore the excitation ladder of cavity polaritons. We measure doubly and triply avoided crossings for pairs and triplets of exciton-polaritons, demonstrating the strong coupling between light and dressed doublet and triplet semiconductor excitations. These results demonstrate that multiply excited excitonic states strongly coupled to a microcavity can be described as two coupled quantum-anharmonic ladders.
@article{arxiv.2004.10845,
title = {The Excitation Ladder of Cavity Polaritons},
author = {Travis M. Autry and Gaël Nardin and Christopher L. Smallwood and Kevin Silverman and Daniele Bajoni and Aristide Lemaître and Sophie Bouchoule and Jacqueline Bloch and Steven Cundiff},
journal= {arXiv preprint arXiv:2004.10845},
year = {2020}
}