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

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.

[1]  Hongxing Xu,et al.  Laterally tunable plasmon resonance in confined biatomic-layer ag nanodisks. , 2010, Nano letters.

[2]  S. J. Park,et al.  Acoustic plasmon on the Au(111) surface. , 2010, Physical review letters.

[3]  A. Politano,et al.  Damping of the surface plasmon in clean and K-modified Ag thin films , 2009 .

[4]  A. Politano,et al.  Annealing effects on the plasmonic excitations of metal/metal interfaces , 2009 .

[5]  Zhe Yuan,et al.  Linear response approach to collective electronic excitations of solids and surfaces , 2009, Comput. Phys. Commun..

[6]  A. Politano,et al.  Probing collective electronic excitations in as-deposited and modified Ag thin films grown on Cu(111) , 2009 .

[7]  Jun Yan,et al.  Plasmon resonances in linear atomic chains: Free-electron behavior and anisotropic screening of d electrons , 2008 .

[8]  K. Emtsev,et al.  Plasmon dispersion and damping in electrically isolated two-dimensional charge sheets , 2008 .

[9]  A. Politano,et al.  Dispersion and Damping of Gold Surface Plasmon , 2008 .

[10]  Zhe Yuan,et al.  Landau damping and lifetime oscillation of surface plasmons in metallic thin films studied in a jellium slab model , 2008 .

[11]  E. Wang,et al.  Growing extremely thin bulklike metal film on a semiconductor surface: Monolayer Al(111) on Si(111) , 2007 .

[12]  Naomi J. Halas,et al.  Plasmonic interactions between a metallic nanoshell and a thin metallic film , 2007 .

[13]  J. M. Pitarke,et al.  Low-energy acoustic plasmons at metal surfaces , 2007, Nature.

[14]  Peter Nordlander,et al.  Plasmonic nanostructures: artificial molecules. , 2007, Accounts of chemical research.

[15]  E. Wang,et al.  Thickness dependence of the surface plasmon dispersion in ultrathin aluminum films on silicon , 2006 .

[16]  R. Agostino,et al.  Plasmon of Shockley surface states in Cu ( 111 ) : A high-resolution electron energy loss spectroscopy study , 2006 .

[17]  M. Henzler,et al.  Crossover between monopole and multipole plasmon of Cs monolayers on Si(111) individually resolved in energy and momentum. , 2006, Physical review letters.

[18]  Zhe Yuan,et al.  Linear-response study of plasmon excitation in metallic thin films: Layer-dependent hybridization and dispersion , 2006 .

[19]  E. Wang,et al.  Thickness dependence of surface plasmon damping and dispersion in ultrathin Ag films , 2005 .

[20]  J. M. Pitarke,et al.  Acoustic surface plasmons in the noble metals Cu, Ag, and Au , 2005, cond-mat/0508725.

[21]  E. Chulkov,et al.  Band structure versus dynamical exchange-correlation effects in surface plasmon energy and damping: a first-principles calculation. , 2004, Physical review letters.

[22]  V. U. Nazarov,et al.  Theory of acoustic surface plasmons , 2004, cond-mat/0409026.

[23]  P. Nordlander,et al.  The effect of a dielectric core and embedding medium on the polarizability of metallic nanoshells , 2002 .

[24]  T. Nagao,et al.  Dispersion and damping of a two-dimensional plasmon in a metallic surface-state band. , 2001, Physical review letters.

[25]  Zhenyu Zhang,et al.  ``Electronic Growth'' of Metallic Overlayers on Semiconductor Substrates , 1998 .

[26]  H. Ishida,et al.  ELECTRONIC EXCITATIONS IN ALKALI-METAL OVERLAYERS. I. UNRECONSTRUCTED LOW-TEMPERATURE PHASE OF LI/AL , 1998 .

[27]  H. Ishida,et al.  ELECTRONIC EXCITATIONS IN ALKALI-METAL OVERLAYERS. II. EFFECTS OF SUBSTITUTIONAL ADSORPTION OF NA/AL(001) , 1998 .

[28]  M. Rocca.  Low-energy EELS investigation of surface electronic excitations on metals , 1995 .

[29]  Liebsch.  Surface-plasmon dispersion and size dependence of Mie resonance: Silver versus simple metals. , 1993, Physical review. B, Condensed matter.

[30]  Gao,et al.  Interaction in a chemisorption system of the submonolayer Cs on the InP(110) substrate. , 1993, Physical review. B, Condensed matter.

[31]  Pi,et al.  Electronic surface excitations of cavities in metals. , 1992, Physical review. B, Condensed matter.

[32]  Ishida,et al.  Electronic excitations in thin alkali-metal layers adsorbed on metal surfaces. , 1992, Physical review. B, Condensed matter.

[33]  Gaspar,et al.  Elementary excitations in alkali-metal overlayers probed by electron-energy-loss spectroscopy: Quantum-mechanical effects. , 1991, Physical review letters.

[34]  Liebsch.  Electronic excitations in adsorbed alkali-metal layers. , 1991, Physical review letters.

[35]  Gao,et al.  Nonmetallic behavior of Cs/GaAs(110). , 1991, Physical review. B, Condensed matter.

[36]  A. Liebsch.  Electronic Screening at Metal Surfaces and the Connection with Physical Phenomena , 1987 .

[37]  Campbell,et al.  Surface energy-loss function for the inelastic scattering of electrons from a metal substrate with an overlayer of adsorbed alkali-metal atoms. , 1985, Physical review. B, Condensed matter.

[38]  Eguiluz.  Self-consistent static-density-response function of a metal surface in density-functional theory. , 1985, Physical review. B, Condensed matter.

[39]  A. Eguiluz.  Dynamical Density Response Function of a Metal Film in the Random-Phase Approximation , 1983 .

[40]  P. Feibelman.  Surface electromagnetic fields , 1982 .

[41]  A. Eguiluz.  Density response function and the dynamic structure factor of thin metal films: Nonlocal effects , 1979 .

[42]  D. Mills.  The scattering of low energy electrons by electric field fluctuations near crystal surfaces , 1975 .

[43]  J. W. Gadzuk.  Coupled Surface-Plasmon Modes in Metal-Thin-Film-Vacuum Sandwiches , 1970 .