Experimental evidence of above-threshold photoemission in solids.

Authors :: Banfi F
Giannetti C
Ferrini G
Galimberti G
Pagliara S
Fausti D
Parmigiani F
Source :: Physical review letters [Phys Rev Lett] 2005 Jan 28; Vol. 94 (3), pp. 037601. Date of Electronic Publication: 2005 Jan 24.
Publication Year :: 2005
Abstract: Nonlinear photoemission from a silver single crystal is investigated by femtosecond laser pulses in a perturbative regime. A clear observation of above-threshold photoemission in solids is reported for the first time. The ratio between the three-photon above-threshold and the two-photon Fermi edges is found to be 10(-4). This value constitutes the only available benchmark for theories aimed at understanding the mechanism responsible for above-threshold photoemission in solids.