Journal Article

Observation of Plasmarons in Quasi-Freestanding Doped Graphene

Polini, Marco, Asgari, Reza, Rotenberg, Eli, Speck, Florian, MacDonald, Allan H, Horn, Karsten, Bostwick, Aaron, Seyller, Thomas

2010

Overview

A hallmark of graphene is its unusual conical band structure that leads to a zero-energy band gap at a single Dirac crossing point. By measuring the spectral function of charge carriers in quasi-freestanding graphene with angle-resolved photoemission spectroscopy, we showed that at finite doping, this well-known linear Dirac spectrum does not provide a full description of the charge-carrying excitations. We observed composite \"plasmaron\" particles, which are bound states of charge carriers with plasmons, the density oscillations of the graphene electron gas. The Dirac crossing point is resolved into three crossings: the first between pure charge bands, the second between pure plasmaron bands, and the third a ring-shaped crossing between charge and plasmaron bands.

• Publisher: American Association for the Advancement of Science,The American Association for the Advancement of Science
• Subject: Atoms & subatomic particles / Band structure of solids / Bands / Charge / Charge carriers / Condensed matter: electronic structure, electrical, magnetic, and optical properties / Density / Doping / Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures / Electronic structure of nanoscale materials : clusters, nanoparticles, nanotubes, and nanocrystals / Electrons / Exact sciences and technology / Excitation spectra / Graphene / Materials science / Momentum / Oscillations / Physics / Plasma diffusion / Plasma interactions / Plasmons / Quantum physics / Quasiparticles / spectral analysis / Spectral bands / spectroscopy / Spectrum analysis