We are interested in the spatio-temporal response of solid state surfaces, nanostructures, and molecules following ultrafast laser excitation. Our goal is to obtain an atomistic understanding of photoinduced processes on (sub-) nanometer length and femtosecond time scales by employing novel pump-probe schemes for ultrafast scanning probe microscopy (SPM). We envision to study, drive and control solid state matter in highly non-equilibrium states on ultrashort length und ultrafast time scales.

To achieve this goal, we are putting efforts into the development of ultrafast scanning probe methods, with a strong focus on broadband THz-gated STM combined with femtosecond optical excitation and all-optical plasmon-assisted femtosecond STM. For more information please check our research page and follow our news below.

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Is hot electron tunneling from a femtosecond laser-excited STM tip thermal or nonthermal? (How) do the femtosecond dynamics of hot electrons inside the tip affect the ultrafast photocurrent response in STM? We have addressed this fundamental question using a THz-gated STM and are pleased that our results are now being published in ACS Nano. (DOI: 10.1021/acsnano.2c04846)

We had a closer look into the nonequilibrium dynamics of hot electrons inside
a photoexcited STM tip, and were curious about the question: does the tunneling of photo-generated hot electrons in STM have thermal or nonthermal character? THz sampling inside the photoexcited STM junction can answer this question, have a closer look at our preprint: https://doi.org/10.48550/arXiv.2205.08248.

After dealing with various technical hurdles, we are finally back to STM operation in our new lab: with cryo and new laser system. Many thanks to the team for the great job to get this running! We are excited to see new data coming out of this machine soon!