CPL - Chalmers Publication Library
| Utbildning | Forskning | Styrkeområden | Om Chalmers | In English In English Ej inloggad.

Symmetry-dependent screening of surface plasmons in ultrathin supported films: The case of Al/Si(111)

Zhe Yuan (Institutionen för teknisk fysik, Material- och ytteori) ; Y. Jiang ; Y. Gao ; Mikael Käll (Institutionen för teknisk fysik, Bionanofotonik) ; Shiwu Gao
Physical Review B (1098-0121). Vol. 83 (2011), 16,
[Artikel, refereegranskad vetenskaplig]

A joint theoretical and experimental study of plasmon excitations for Al overlayers on Si(111) has been carried out. The presence of the substrate is found to drastically modify the hybridization and charge density response of the surface plasmons of the metal overlayers. The symmetric mode, which is polarized toward the Al/Si interface, is strongly damped in intensity and significantly redshifted in energy. However, the antisymmetric mode, which is polarized to the metal-vacuum interface, is essentially unaffected by the presence of the substrate. A low-energy acoustic plasmon mode is also found in a one monolayer Al film and is almost unaffected by the substrate. The calculated plasmon dispersions with substrate are in good agreement with experimental data measured by electron energy loss spectroscopy. Our results suggest that interaction and screening at the subnanometer scale are symmetry dependent, a conclusion that may have general implications in other thin films and related structures.

Nyckelord: alkali-metal overlayers, density-response function, electronic, excitations, thin-films, energy, dispersion, scattering, substrate, layers, phase



Denna post skapades 2011-06-07. Senast ändrad 2012-06-19.
CPL Pubid: 141387

 

Läs direkt!

Lokal fulltext (fritt tillgänglig)

Länk till annan sajt (kan kräva inloggning)


Institutioner (Chalmers)

Institutionen för teknisk fysik, Material- och ytteori (1900-2015)
Institutionen för teknisk fysik, Bionanofotonik (2007-2015)
Institutionen för fysik (GU) (GU)

Ämnesområden

Fysik
Den kondenserade materiens fysik

Chalmers infrastruktur