Download file (1.7 MB)
Download as zip (1.26 MB)

Collection

Citation

Description:

We use momentum-dependent electron energy-loss spectroscopy in transmission to study collective charge excitations in the "strange" layer metal Sr2RuO4. We cover a complete range between in-plane and out-of-plane oscillations. Outside of the classical range of electron-hole excitations, leading to a Landau damping, we observe well defined plasmons. The optical (acoustic) plasmon due to an in-phase (out-of-phase) charge oscillation of neighbouring layers exhibits a quadratic (linear) dispersion. Using a model for the Coulomb interaction of the charges in a lay- ered system, it is possible to describe the complete range of plasmon excitations in a mean-field random phase approximation without taking correlation effects into account. There are no signs of over-damped plasmons predicted by holographic theories. This indicates that long wave- length charge excitations are not influenced by local correlation effects such as on-site Coulomb interaction and Hund’s exchange interaction.

Rights:

• Creative Commons BY Attribution 4.0 International
  

Keyword: Sr2RuO4, Plasmon

Date published: 2025-05-08

Publisher: Springer Science and Business Media LLC

Journal:

• Nature Communications (ISSN: 20411723) vol. 16 issue. 1 4287

Funding:

• EC | Horizon 2020 Framework Programme 101094299
• Deutsche Forschungsgemeinschaft 461150024
• Deutsche Forschungsgemeinschaft 461150024

Manuscript type: Publisher's version (Version of record)

MDR DOI:

First published URL: https://doi.org/10.1038/s41467-025-58978-x

Related item:

Other identifier(s):

Contact agent:

Updated at: 2025-05-22 15:26:48 +0900

Published on MDR: 2025-05-23 08:24:34 +0900