Experimental evidence of above-threshold photoemission in solids.
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.
Banfi
Francesco
F
Istituto Nazionale per la Fisica della Materia and Dipartimento di Matematica e Fisica, Università Cattolica, I-25121 Brescia, Italy.
Giannetti
Claudio
C
Ferrini
Gabriele
G
Galimberti
Gianluca
G
Pagliara
Stefania
S
Fausti
Daniele
D
Parmigiani
Fulvio
F