Naslov
Ultrafast dynamics of (quasi-1D) Pb overlayers grown on flat and vicinal Si(111)

Autori
Syed, Abdul Samad ; Mikšić Trontl, Vesna ; Ligges, Manuel ; Sandhofer, Mathias ; Agarwal, Ishita ; Lükermann, Daniel ; Tegenkamp, Christoph ; Pfnür, Herbert ; Bovensiepen, Uwe

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Skup
Verhandlungen der Deutschen Physikalischen Gesellschaft 2015

Mjesto i datum
Berlin, Njemačka, 15.03.2015. - 20.03.2015

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
ultrafast dynamics

Sažetak
Due to real space anisotropy of the vicinal Si(111) surfaces, hot electrons can be expected to exhibit different dynamics along and perpendicular to the steps as compare to the Si(111) flat surface. We made a comparative study of Pb overlayer structures grown on vicinal Si (557) and flat Si (111) using femtosecond time- and angle- resolved two-photon photoemission. We mapped the unoccupied electronic band structure near Γ and find that both systems have two unoccupied states at E−EF=3.3 and 3.5 eV. In pump-probe experiments combined with a position sensitive electron time of flight spectrometer we analyze the ultrafast momentum dependent electron dynamics along two in plane directions. On vicinal surfaces we observe a specific, momentum dependent population dynamics which are absent on the flat surface. This signature shows a delay in population build up of 5 fs as a function of angle with respect to the terrace direction. We assign this behavior to step-induced scattering. We gratefully acknowledge funding by the DFG through FOR1700.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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