Details

Autor(en) / Beteiligte

• Güdde, J
• Rohleder, M
• Meier, T
• Koch, S.W
• Höfer, U

Titel

Time-Resolved Investigation of Coherently Controlled Electric Currents at a Metal Surface

Ist Teil von

• Science (American Association for the Advancement of Science), 2007-11, Vol.318 (5854), p.1287-1291

Ort / Verlag

Washington, DC: American Association for the Advancement of Science

Erscheinungsjahr

2007

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Studies of current dynamics in solids have been hindered by insufficiently brief trigger signals and electronic detection speeds. By combining a coherent control scheme with photoelectron spectroscopy, we generated and detected lateral electron currents at a metal surface on a femtosecond time scale with a contact-free experimental setup. We used coherent optical excitation at the light frequencies ωa and ωa/2 to induce the current, whose direction was controlled by the relative phase between the phase-locked laser excitation pulses. Time- and angle-resolved photoelectron spectroscopy afforded a direct image of the momentum distribution of the excited electrons as a function of time. For the first (n = 1) image-potential state of Cu(100), we found a decay time of 10 femtoseconds, attributable to electron scattering with steps and surface defects.