Download file (758 KB)
Download as zip (667 KB)

Collection

Citation

Description:

Fermi liquids respond differently to perturbations depending on whether their frequency is larger (collisionless regime) or smaller (hydrodynamic regime) than the inter-particle collision rate. This results in a different phase velocity between the collisionless zero sound and hydrodynamic first sound. We performed terahertz photocurrent nanoscopy measurements on graphene devices, with a metallic gate in close proximity to the sample, to investigate acoustic plasmons, the counterpart of sound modes in electronic Fermi liquids. We report the observation of a change in the phase velocity of acoustic plasmons in graphene when the excitation frequency approaches the electron- electron collision rate. This first observation of the first sound mode in an electronic Fermi liquid is of fundamental interest and can enable novel terahertz emitter and detection concepts.

Rights:

• Creative Commons BY-NC Attribution-NonCommercial 4.0 International
  

Keyword: Fermi liquids, terahertz photocurrent nanoscopy, acoustic plasmons

Date published: 2023-09-29

Publisher: American Association for the Advancement of Science (AAAS)

Journal:

• Science Advances (ISSN: 23752548) vol. 9 issue. 39 eadi0415

Funding:

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

MDR DOI:

First published URL: https://doi.org/10.1126/sciadv.adi0415

Related item:

Other identifier(s):

Contact agent:

Updated at: 2025-02-23 22:46:24 +0900

Published on MDR: 2025-02-23 22:46:24 +0900