Lifetime of electronic excitations in metal nanoparticles

9 páginas, 4 figuras.-- Trabajo presentado al "6th International Meeting on Photodynamics" celebrado en La Habana (Cuba) del 1 al 5 de febrero de 2010.Electronic excitations in metal particles with sizes up to a few nanometers are shown to have a one-electron character when a laser pulse is applied off the plasmon resonance. The calculated lifetimes of these excitations are in the femtosecond timescale but their values are substantially different from those in bulk. This deviation can be explained from the large weight of the excitation wave function in the nanoparticle surface region, where dynamic screening is significantly reduced. The well-known quadratic dependence of the lifetime with the excitation energy in bulk breaks down in these finite-size systems.We acknowledge the partial support of the Basque Government, the University of the Basque Country UPV/EHU (grant no. 9/UPV 00206.215-13639/2001) and the Spanish MEC (grants FIS2007-66711-C02-02 and MAT2008-06843-C03-01). JAA acknowledges the financial support of Ikerbasque.Peer reviewe

Lifetime of electronic excitations in metal nanoparticles

9 páginas, 4 figuras.-- Trabajo presentado al "6th International Meeting on Photodynamics" celebrado en La Habana (Cuba) del 1 al 5 de febrero de 2010.Electronic excitations in metal particles with sizes up to a few nanometers are shown to have a one-electron character when a laser pulse is applied off the plasmon resonance. The calculated lifetimes of these excitations are in the femtosecond timescale but their values are substantially different from those in bulk. This deviation can be explained from the large weight of the excitation wave function in the nanoparticle surface region, where dynamic screening is significantly reduced. The well-known quadratic dependence of the lifetime with the excitation energy in bulk breaks down in these finite-size systems.We acknowledge the partial support of the Basque Government, the University of the Basque Country UPV/EHU (grant no. 9/UPV 00206.215-13639/2001) and the Spanish MEC (grants FIS2007-66711-C02-02 and MAT2008-06843-C03-01). JAA acknowledges the financial support of Ikerbasque.Peer reviewe