Exciton Mott transition in Si is investigated by using terahertz time-domain spectroscopy. The excitonic correlation as manifested by the 1s-2p resonance is observed above the Mott density. The scattering rate of charge carriers is prominently enhanced at the proximity of Mott density, which is attributed to the non-vanishing exciton correlation in the metallic electron-hole plasma. Concomitantly, the signature of plasmon-exciton coupling is observed in the loss function spectra.
@article{arxiv.1203.5179,
title = {Exciton Mott transition in Si Revealed by Terahertz Spectroscopy},
author = {Takeshi Suzuki and Ryo Shimano},
journal= {arXiv preprint arXiv:1203.5179},
year = {2015}
}