Effects of confinement on the electron and lattice dynamics in metal nanoparticles
Laboratoire de Spectrométrie Ionique et Moléculaire, CNRS and Université Lyon I, 43 boulevard du 11 novembre 1918, 69622 Villeurbanne, France
2 Centre de Physique Moléculaire Optique et Hertzienne, CNRS and Université Bordeaux I, 351 cours de la Libération, 33405 Talence, France
Corresponding author: a firstname.lastname@example.org
Published online: 13 July 2005
Effects of confinement on the electron-electron (e-e) and electron-phonon (e-ph) thermalization dynamics in noble metal clusters are calculated using simple approaches. The model predictions are compared with femtosecond pump-probe measurements which display an acceleration of the e-e and e-ph relaxation dynamics. The size-effects on the e-e relaxation dynamics are consistent with a model involving the surface-induced reduction of the screening efficiency of the Coulomb e-e interaction. With regard to the e-ph relaxation dynamics, this model yields too large time constants, pointing out deficiencies of the standard modelling of the e-ph energy exchanges in bulk metals. Analysis of these deficiencies shows that the bare e-ion interaction has to be involved in the transition matrix element describing the non-adiabatic e-ph energy exchanges.
PACS: 36.40.-c – Atomic and molecular clusters / 78.47.+p – Time-resolved optical spectroscopies and other ultrafast optical measurements in condensed matter / 42.65.-k – Nonlinear optics
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005