Experimental signatures of the transition from acoustic plasmon to electronic sound in graphene.

Autor: Barcons Ruiz D; ICFO - Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss 3, 08860 Castelldefels (Barcelona), Spain., Hesp NCH; ICFO - Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss 3, 08860 Castelldefels (Barcelona), Spain., Herzig Sheinfux H; ICFO - Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss 3, 08860 Castelldefels (Barcelona), Spain., Ramos Marimón C; ICFO - Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss 3, 08860 Castelldefels (Barcelona), Spain., Maissen CM; CIC nanoGUNE, 20018 Donostia-San Sebastián, Spain., Principi A; Department of Physics and Astronomy, The University of Manchester, M13 9PL Manchester, UK., Asgari R; School of Physics, Institute for Research in Fundamental Sciences, IPM, Tehran 19395-5531, Iran.; School of Physics, University of New South Wales, Kensington, NSW 2052, Australia., Taniguchi T; International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan., Watanabe K; Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan., Polini M; ICFO - Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss 3, 08860 Castelldefels (Barcelona), Spain.; Dipartimento di Fisica, Università di Pisa, Largo Bruno Pontecorvo 3, I-56127 Pisa, Italy.; Istituto Italiano di Tecnologia, Graphene Labs, Via Morego 30, I-16163 Genova, Italy., Hillenbrand R; CIC nanoGUNE, 20018 Donostia-San Sebastián, Spain.; CIC nanoGUNE BRTA and Department of Electricity and Electronics, UPV/EHU, 20018 Donostia-San Sebastián, Spain.; IKERBASQUE, Basque Foundation for Science, Bilbao, Spain., Torre I; ICFO - Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss 3, 08860 Castelldefels (Barcelona), Spain., Koppens FHL; ICFO - Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss 3, 08860 Castelldefels (Barcelona), Spain.; ICREA-Institucio Catalana de Recerca i Estudis Avancats, 08010 Barcelona, Spain.
Jazyk: angličtina
Zdroj: Science advances [Sci Adv] 2023 Sep 29; Vol. 9 (39), pp. eadi0415. Date of Electronic Publication: 2023 Sep 29.
DOI: 10.1126/sciadv.adi0415
Abstrakt: Fermi liquids respond differently to perturbations depending on whether their frequency is higher (collisionless regime) or lower (hydrodynamic regime) than the interparticle collision rate. This results in a different phase velocity between the collisionless zero sound and the hydrodynamic first sound. We performed terahertz photocurrent nanoscopy measurements on graphene devices, with a metallic gate close to the graphene layer, to probe the dispersion of propagating acoustic plasmons, the counterpart of sound modes in electronic Fermi liquids. We report the observation of a change in the plasmon phase velocity when the excitation frequency approaches the electron-electron collision rate that is compatible with the transition between the zero and the first sound mode.
Databáze: MEDLINE