Observations of Plasmarons in a System of Massive Electrons

TL;DR

This paper reports the first experimental observation of plasmarons in a system of massive electrons using tunneling spectroscopy, revealing new magnetoplasmaron features under magnetic fields.

Contribution

It provides the first detection of plasmarons in massive electron systems and uncovers magnetoplasmarons, expanding understanding of electron-plasmon interactions.

Findings

First detection of plasmarons in massive electron systems

Observation of magnetoplasmarons at high energies

Long-lived quasiparticle features in broadened SPDOS

Abstract

Calculations of the single particle density of states (SPDOS) of electron liquids have long predicted that there exist two distinct charged excitations: the usual quasiparticle consisting of an electron or hole screened by a correlation hole, and a "plasmaron" consisting of a hole resonantly bound to real plasmons in the Fermi sea(1,2). Using tunneling spectroscopy to measure the SPDOS of a two-dimensional electronic system, we demonstrate the first detection of the plasmaron in a system in which electrons have mass. We monitor the evolution of the plasmaron with applied magnetic field and discover unpredicted "magnetoplasmarons" which appear in spectra as negative index Landau levels. These sharp features corresponding to long-lived quasiparticles appear at high energies where SPDOS structure is ordinarily broadened by electron-electron interactions.