The quasi two-dimensional electron gas on a metal film can transmit to the surface even minute mechanical disturbances occurring in the depth, thus allowing the gentlest of all surface probes, helium atoms, to perceive the vibrations of the deepest atoms via the induced surface-charge density oscillations. A density functional perturbation theory (DFPT) and a helium atom scattering study of the phonon dispersion curves in lead films of up to 7 mono-layers on a copper substrate show that: (a) the electron-phonon interaction is responsible for the coupling of He atoms to in-depth phonon modes; and (b) the inelastic HAS intensity from a given phonon mode is proportional to its electron-phonon coupling. The direct determination of mode-selected electron-phonon coupling strengths has great relevance for understanding superconductivity in thin films and two-dimensional systems. This journal is © the Partner Organisations 2014

Benedek, G., Bernasconi, M., Bohnen, K., Campi, D., Chulkov, E., Echenique, P., et al. (2014). Unveiling mode-selected electron-phonon interactions in metal films by helium atom scattering. PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 16(16), 7159-7172 [10.1039/c3cp54834a].

Unveiling mode-selected electron-phonon interactions in metal films by helium atom scattering

BENEDEK, GIORGIO
Primo
;
BERNASCONI, MARCO
Secondo
;
CAMPI, DAVIDE;
2014

Abstract

The quasi two-dimensional electron gas on a metal film can transmit to the surface even minute mechanical disturbances occurring in the depth, thus allowing the gentlest of all surface probes, helium atoms, to perceive the vibrations of the deepest atoms via the induced surface-charge density oscillations. A density functional perturbation theory (DFPT) and a helium atom scattering study of the phonon dispersion curves in lead films of up to 7 mono-layers on a copper substrate show that: (a) the electron-phonon interaction is responsible for the coupling of He atoms to in-depth phonon modes; and (b) the inelastic HAS intensity from a given phonon mode is proportional to its electron-phonon coupling. The direct determination of mode-selected electron-phonon coupling strengths has great relevance for understanding superconductivity in thin films and two-dimensional systems. This journal is © the Partner Organisations 2014
Articolo in rivista - Articolo scientifico
surface phonons, electron-phonon interaction, density functional theory
English
2014
16
16
7159
7172
none
Benedek, G., Bernasconi, M., Bohnen, K., Campi, D., Chulkov, E., Echenique, P., et al. (2014). Unveiling mode-selected electron-phonon interactions in metal films by helium atom scattering. PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 16(16), 7159-7172 [10.1039/c3cp54834a].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/56111
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