Low-temperature UHV STM-AFM with optical acces on two sides

• Subject Area: Condensed Matter Physics
• Term: Funded in 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 546266657

The proposed STM-AFM with optical access will be used to study light-matter interactions in low-dimensional systems with atomic resolution. Here, high-resolution scanning probe microscopy (STM, AFM and KPFM) provides insights into the electronic, geometric and chemical structure of individual adsorbates or extended two-dimensional materials. The combination with movable parabolic mirrors directed at the tip apex also allows optical signals from the tip-sample transition to be detected. By selectively driving optically excited states through the highly localized tunnel current, optical and vibronic properties of a variety of materials can be investigated at the atomic level. With the proposed system, experiments are explicitly planned to investigate 1) charge carrier and exciton dynamics and localization of excited states in molecular 2D architectures and van der Waals materials, 2) structure-property relationships at the single-molecule level, 3) photochemical processes with single-bond resolution, and 4) novel decoupling strategies and strategies for influencing exciton dynamics in molecular complexes through surface templating. In particular, collaborations are planned with groups from the Faculty of Physics and Chemistry. In addition to electroluminescence-based experiments, the proposed system offers the possibility of extension to optical and THz spectroscopy. This enables real-time experiments on laser and exciton dynamics in low-dimensional structures, also in coordination with other groups at the University of Göttingen. The achievable spatial resolution in the sub-nanometer range and the precise control of the tip-sample cavity provide complementary insights into the real-time dynamics of light-induced phenomena to the existing experimental methods. The proposed instrument provides the basis for this.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Tieftemperatur UHV STM-AFM mit beidseitigem optischen Zugang
• Instrumentation Group: 5091 Rasterkraft-Mikroskope
• Applicant Institution: Georg-August-Universität Göttingen
• Leader: Professorin Dr. Katharina Kaiser