The dynamics of an electron-hole plasma governed by strong Coulomb interaction is a challenging many-body problem.We report on experimental realization of electron-hole many-body states in the picosecond time scale, with tunable densities in a representative semiconductor Cu2O. By using time-resolved optical-pump terahertz third-harmonic-generation spectroscopy, we study the nonlinear terahertz dynamical characteristics of the many-body electron-hole states. We find not only efficient and nonperturbative terahertz third-harmonic yield associated with the excitonic formation, but also a nonmonotonic dependence of the excitonic nonlinear response on the electron-hole density, reflecting the exciton dissociation at high charge density. Our results provide an efficient excitonic sensing of the far-from-equilibrium electron-hole many-body states.
@article{arxiv.2501.09535,
title = {Distinct terahertz third-harmonic generation of many-body excitonic states},
author = {Changqing Zhu and Anneke Reinold and Patrick Pilch and Sergey Kovalev and Julian Heckötter and Doris Reiter and Manfred Bayer and Marc Assmann and Zhe Wang},
journal= {arXiv preprint arXiv:2501.09535},
year = {2025}
}