We measure direct multiphoton photoemission of the Au(111) surface state with 800-nm laser pulses. We observe the parabolic dispersion in the angular distribution of photoelectrons having absorbed between four and seven photons. The k dispersion we measure can be explained in terms of Shockley-state replicas, with a nascent hot electrons distribution at k above the Fermi level. Moderate laser power densities, of the order of 100 GW/cm2 , resulted in large electron yields, indicating the importance of multiphoton excitations to define the electronic and magnetic properties of matter in the first hundred femtoseconds after laser excitation.
Multiphoton k-resolved photoemission from gold surface states with 800-nm femtosecond laser pulses / F. Sirotti, N. Beaulieu, A. Bendounan, M.G. Silly, C. Chauvet, G. Malinowski, G. Fratesi, V. Véniard, G. Onida. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - 90:3(2014), pp. 035401.1-035401.6.
Multiphoton k-resolved photoemission from gold surface states with 800-nm femtosecond laser pulses
G. Fratesi;G. OnidaUltimo
2014
Abstract
We measure direct multiphoton photoemission of the Au(111) surface state with 800-nm laser pulses. We observe the parabolic dispersion in the angular distribution of photoelectrons having absorbed between four and seven photons. The k dispersion we measure can be explained in terms of Shockley-state replicas, with a nascent hot electrons distribution at k above the Fermi level. Moderate laser power densities, of the order of 100 GW/cm2 , resulted in large electron yields, indicating the importance of multiphoton excitations to define the electronic and magnetic properties of matter in the first hundred femtoseconds after laser excitation.Pubblicazioni consigliate
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