RT Journal Article
SR Electronic
T1 Observation of Plasmarons in Quasi-Freestanding Doped Graphene
JF Science
JO Science
FD American Association for the Advancement of Science
SP 999
OP 1002
DO 10.1126/science.1186489
VO 328
IS 5981
A1 Bostwick, Aaron
A1 Speck, Florian
A1 Seyller, Thomas
A1 Horn, Karsten
A1 Polini, Marco
A1 Asgari, Reza
A1 MacDonald, Allan H.
A1 Rotenberg, Eli
YR 2010
UL http://science.sciencemag.org/content/328/5981/999.abstract
AB 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.