Rostock 2019 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 24: Poster: Quantum Optics and Photonics I

Q 24.14: Poster

Tuesday, March 12, 2019, 16:30–18:30, S Fobau Physik

Few-cycle laser pulse illumination of a nanoscale junction in an ambient-conditioned STM — •Jonas Heimerl, Takuya Higuchi, Maximilian Ammon, Alexander Schneider, and Peter Hommelhoff — Department Physik, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91058 Erlangen

Metal needle tips render a perfect model system to investigate nonlinear light-matter interaction using few-cycle laser pulse illumination since they show large optical field enhancement at the tip apex. This enhancement enables peak electric fields above 1 V/Å while keeping the pulse energy sufficiently low, in order to prevent material damage. Such large electric fields lead to strong-field effects at the apex of the tips, such as rescattering of electrons. Moreover, nanometer sharp tips play an important role in scanning tunneling microscopes (STM), where a tip and a flat sample form a nanoscale junction. When this junction is illuminated with few-cycle laser pulses, the local electric fields are expected to be even more enhanced due to the coupling of optical near-fields between tip and metallic sample. This effect can also be observed in tip-enhanced Raman spectroscopy. We discuss the operation of a home-built ambient-conditioned STM under illumination of few-cycle laser pulses. The nanometer-precision control of the junction in STM operation allows us to precisely investigate the optical near-fields arising in the junction.