Regensburg 2016 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 71: Scanning Probe Techniques and New Experimental Methods
O 71.4: Poster
Mittwoch, 9. März 2016, 18:15–20:30, Poster A
Fast electronic pump-probe spectroscopy using shaped sub-nanosecond pulses — •Gregory McMurtrie1,2, Jacob Burgess1,2, Steffen Rolf-Pissarczyk1,2, and Sebastian Loth1,2 — 1Max-Planck Institut für Struktur und Dynamik der Materie — 2Max-Planck Institut für Festkörperforschung
Pump-probe schemes make it possible to measure fast dynamical processes with the scanning tunneling microscope (STM). Electronic pump-probe spectroscopy excites and detects dynamics using voltage pulses [1] with the time scale being set by the speed at which the voltage can be changed at the tunnel junction [2], [3].
We use time domain reflectometry to measure the transmission characteristics of a low-temperature STM. Damping in the cabling and standing waves at various points of the transmission line smear the edges of the pump and probe pulses and limit the achievable time resolution. By extracting amplitude and phase information from the reflectometry measurements it is possible to compensate these imperfections and create a shaped input pulse which will have sharp edges at the STM tunnel junction. This process can shape pulses with a bandwidth of up to 3 GHz, enabling sub-nanosecond time resolution.
Pushing electronic pump-probe spectroscopy beyond the nanosecond range will enable a wide range of experiments that harness the strong interaction of electrons with spin, charge and vibration excitations.
[1] S. Loth, et al., Science 329 1628 (2010).
[2] C. Saunus, et al., Appl. Phys. Lett. 102 051601 (2013).
[3] C. Grosse, et al. Appl. Phys. Lett. 103 183108 (2013).