Details
| Original language | English |
|---|---|
| Article number | 033017 |
| Journal | New Journal of Physics |
| Volume | 12 |
| Publication status | Published - 11 Mar 2010 |
Abstract
The sheet plasmon in epitaxially grown graphene layers on SiC(0001) and the influence of surface roughness have been investigated in detail by means of low-energy electron diffraction (LEED) and electron energy loss spectroscopy (EELS). We show that the existence of steps or grain boundaries in this epitaxial system is a source of strong damping, while the dispersion is rather insensitive to defects. To the first order, the lifetime of the plasmons was found to be proportional to the average terrace length and to the plasmon wavelength. A possible reason for this surprisingly efficient plasmon damping may be the close coincidence of phase (and group) velocities of the plasmons (almost linear dispersion) with the Fermi velocity of the electrons. Therefore, uncorrelated defects like steps only have to act as a momentum source to effectively couple plasmons to the electron-hole continuum.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- General Physics and Astronomy
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In: New Journal of Physics, Vol. 12, 033017, 11.03.2010.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Plasmon damping below the Landau regime
T2 - The role of defects in epitaxial graphene
AU - Langer, Thomas
AU - Baringhaus, J.
AU - Pfnür, Herbert
AU - Schumacher, H. W.
AU - Tegenkamp, Christoph
PY - 2010/3/11
Y1 - 2010/3/11
N2 - The sheet plasmon in epitaxially grown graphene layers on SiC(0001) and the influence of surface roughness have been investigated in detail by means of low-energy electron diffraction (LEED) and electron energy loss spectroscopy (EELS). We show that the existence of steps or grain boundaries in this epitaxial system is a source of strong damping, while the dispersion is rather insensitive to defects. To the first order, the lifetime of the plasmons was found to be proportional to the average terrace length and to the plasmon wavelength. A possible reason for this surprisingly efficient plasmon damping may be the close coincidence of phase (and group) velocities of the plasmons (almost linear dispersion) with the Fermi velocity of the electrons. Therefore, uncorrelated defects like steps only have to act as a momentum source to effectively couple plasmons to the electron-hole continuum.
AB - The sheet plasmon in epitaxially grown graphene layers on SiC(0001) and the influence of surface roughness have been investigated in detail by means of low-energy electron diffraction (LEED) and electron energy loss spectroscopy (EELS). We show that the existence of steps or grain boundaries in this epitaxial system is a source of strong damping, while the dispersion is rather insensitive to defects. To the first order, the lifetime of the plasmons was found to be proportional to the average terrace length and to the plasmon wavelength. A possible reason for this surprisingly efficient plasmon damping may be the close coincidence of phase (and group) velocities of the plasmons (almost linear dispersion) with the Fermi velocity of the electrons. Therefore, uncorrelated defects like steps only have to act as a momentum source to effectively couple plasmons to the electron-hole continuum.
UR - http://www.scopus.com/inward/record.url?scp=77951196887&partnerID=8YFLogxK
U2 - 10.1088/1367-2630/12/3/033017
DO - 10.1088/1367-2630/12/3/033017
M3 - Article
AN - SCOPUS:77951196887
VL - 12
JO - New Journal of Physics
JF - New Journal of Physics
SN - 1367-2630
M1 - 033017
ER -