Experimental evidence of above-threshold photoemission in solids
arXiv:1201.3049 · doi:10.1103/PhysRevLett.94.037601
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.
5 pages, 4 figures