Acoustic plasmons at the crossover between the collisionless and hydrodynamic regimes in two-dimensional electron liquids
Abstract
Hydrodynamic flow in two-dimensional electron systems has so far been probed only by dc transport and scanning gate microscopy measurements. In this work we discuss theoretically signatures of the hydrodynamic regime in near-field optical microscopy. We analyze the dispersion of acoustic plasmon modes in two-dimensional electron liquids using a non-local conductivity that takes into account the effects of (momentum-conserving) electron-electron collisions, (momentum-relaxing) electron-phonon and electron-impurity collisions, and many-body interactions beyond the celebrated Random Phase Approximation. We derive the dispersion and, most importantly, the damping of acoustic plasmon modes and their coupling to a near-field probe, identifying key experimental signatures of the crossover between collisionless and hydrodynamic regimes.
Keywords
Cite
@article{arxiv.1812.09889,
title = {Acoustic plasmons at the crossover between the collisionless and hydrodynamic regimes in two-dimensional electron liquids},
author = {Iacopo Torre and Luan Vieira de Castro and Ben Van Duppen and David Barcons Ruiz and François M. Peeters and Frank H. L. Koppens and Marco Polini},
journal= {arXiv preprint arXiv:1812.09889},
year = {2019}
}
Comments
14 pages, 4 figures