We report on studies of charge carrier plasmon excitations in Sr2RuO4 by transmission Electron Energy-Loss Spectroscopy. In particular, we present results on the plasmon dispersion and its width as a function of momentum transfer. The dispersion can be qualitatively explained in the framework of RPA calculations, using an unrenormalized tight-binding band structure. The constant long-wavelength width of the plasmon indicates, that it is caused by a decay into inter-band transition and not by quantum critical fluctuations. The results from these studies on a prototypical bad metal system show that the long-wavelength plasmon excitations near 1 eV are caused by resilient quasiparticles and are not influenced by correlation effects.
Cite
@article{arxiv.2210.06960,
title = {Propagating charge carrier plasmon in Sr2RuO4},
author = {Martin Knupfer and Fabian Jerzembeck and Naoki Kikugawa and Friedrich Roth and Joerg Fink},
journal= {arXiv preprint arXiv:2210.06960},
year = {2022}
}