Dresden 2017 – wissenschaftliches Programm
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MI: Fachverband Mikrosonden
MI 7: Poster: Microanalysis and Microscopy
MI 7.11: Poster
Mittwoch, 22. März 2017, 18:00–20:00, P4
An optical setup for focusing THz radiation on a Scanning Tunneling Microscope tip — Mohamad Abdo1,2, •Steffen Rolf-Pissarczyk1,2, Jacob Burgess1,2, Björn Schlie1,2, and Sebastian Loth1,2,3 — 1Max-Planck-Institut für Struktur und Dynamik der Materie, Hamburg — 2Max-Planck-Institut für Festkörperforschung, Stuttgart — 3Institut für Funktionelle Materie und Quantentechnologien, Universität Stuttgart
Terahertz (THz) radiation lies between Microwave radiation and Infrared light in the electromagnetic spectrum. It can be generated for example by optical rectification of femtosecond laser pulses in non-linear crystals. However, the power of the generated THz is typically very weak. This often stands as an obstacle against measurements with weak signal amplitudes, in particular THz-induced tunneling in a scanning tunneling microscope (STM) where the THz electric field couples to the STM tip and enables highly localized transport measurements at picosecond speed [1,2].
Here we show the development of an optical setup that is optimized for THz-induced transport experiments. We also show how to manipulate the THz pulse shape by de-compression of the excitation pulse.
This setup enables studies of ultrafast physical phenomena with the atomic spatial resolution provided by the STM even in tunneling regimes where significantly less than one electron tunnels per THz pulse.
[1] T. Cocker, et al., Nature Photonics 7 620-625 (2013).
[2] T. Cocker, et al., Nature 539, 263-267 (2016).