Dresden 2017 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 3: Scanning Probe Techniques: Method Development I
O 3.1: Vortrag
Montag, 20. März 2017, 10:30–10:45, TRE Phy
Characterization and Optimization of High Frequency STM — •Gregory McMurtie1,2, Max Hänze1,2, Jacob Burgess1,2, 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
Injecting coherent pulses (pump-probe[1]) or continuous wave signals (spin-resonance[2] ) into a tunnel junction has shown promising results for the characterization of fast magnetic surface dynamics using STM. When pushing into the sub-nanosecond time domain, the transmission line characteristics of the instrument strongly modify the signals reaching to the tunnel junction. This is caused by impedance mismatches in the cabling that express as reflections, resonant cavities, or low-pass filtering. We present an in-situ technique for the quantitative measurement of transmission line characteristics. Both amplitude and phase information are detected and generate a more accurate picture of the tunnel junction than conventional high frequency characterization methods. This information is used to compensate for imperfections in the transmission lines, resulting in a greatly increased effective bandwidth. By improving the time resolution of the STM, the door is opened to observe a wide range of ultra-fast phenomena at the atomic scale. Additionally, the access to phase information hints at the possibility of observing coherent excitation's.
[1] S. Loth, A. J. Heinrich et. al, Science 329 1628 (2010). [2] S. Baumann, W. Paul, A. J. Heinrich et al., Science 350 6259 (2015)