Regensburg Center for Ultrafast Nanoscopy

RTG Colloquium:Prof. Dr. Rudolf Bratschitsch
2026-01-16 14:00 - 15:00 (Europe/Berlin)
Venue: RUN auditorium 1st floor

Title: Magnonic waveguide networks

University of Münster

Spin waves (magnons) have emerged as a promising platform for next-generation physical computing. However, current experimental realizations of magnonic waveguides suffer from limited spin-wave propagation lengths and inefficient dispersion tuning capabilities. In my talk, I will present low-loss magnonic waveguides in a thin magnetic insulator film, fabricated with a new maskless silicon ion implantation technique. We demonstrate a large-scale magnonic network, paving the way for wafer-scale magnonic integrated circuits.

RTG Colloquium:Dr. Anna Rosławska
2026-01-23 14:00 - 15:00
Venue: RUN auditorium 1st floor

Single-molecule optics with atomic precisionMPI for Solid State Research StuttgartLuminescence, photosynthesis, and energy harvesting rely on processes originating at the spatial scale of individual molecules. Investigating the details of these mechanisms requires reaching subnm precision in optics, which becomes possible by combining optical spectroscopy with scanningprobe microscopy. In my talk, I will discuss how atomic-scale optics can be used to study the optical properties of single molecules and to drive photochemistry with sub-nm precision.

Young Colloquium:The Other Climate Crisis
2026-01-29 16:15 - 17:45
As Earth warms, regional climate signals are accumulating. Some signals, for example, land warming more than the ocean and the Arctic warming the most, were expected and successfully predicted. Underlying this success was the application of physical laws across a hierarchy of complexity. With additional warming, however, discrepancies between real-world signals and expectations are piling up, especially at regional scales.

The talk will provide an overview of the successes and discrepancies of physics based climate modeling and the paths forward which include using signals to test assumptions and processes driving a warming Earth for the first time, developing testable hypotheses, and revitalizing conceptual thinking by filling gaps across climate-system components and spatial scales.

Prof. Tiffany Shaw

University of Chicago, Geophysical Sciences

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RTG Colloquium:Prof. Dr. Renske van der Veen
2026-01-30 14:00 - 15:00
Venue: RUN auditorium 1st floor

Fast electrons and hard X-rays for unraveling atomic-scale dynamics in light-energy conversionDepartment Atomic-Scale Dynamics in Light-Energy Conversion, Helmholtz Zentrum Berlin

The increasing demand for renewable and low-cost energy motivates intensive research aimed at characterizing and optimizing materials that can efficiently convert (sun) light into usable energy in the form of electricity or chemical fuels. Conventional characterization techniques either lack the spatialresolution necessary to resolve individual atoms, or they lack the temporal resolution required to capture structural rearrangements as they evolve. Our group develops complementary X-ray and electron-based tools to visualize light-induced processes in materials on atomic length and time scales. In this talk I will introduce you to the techniques of ultrafast/time-resolved X-ray spectroscopy and transmission electron microscopy and provide several examples of how these techniques can be used in the fields of solar energy and catalysis.

Young Colloquium:Abschlussveranstaltung
2026-02-05 16:15 - 17:45
Prof. Ferdinand Evers,Franziska Fröhlich, Philipp Erhardt, Simon Spörl

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Oliver Graydon, PhD, Chief Editor of Nature Photonics, visits the RUN
2026-04-20 16:00 - 17:00
On Monday, April 20, 2026, Oliver Graydon, chief editor of Nature Photonics, will visit the RUN. In addition to scientific discussions and lab tours, a highlight of his visit will be his lecture on “The Role of AI in scientific publishing.” For more information, click here.

RTG Colloquium: Zhiyang Zeng
2026-04-24 14:00 - 15:00
Condensed Matter Dynamics DepartmentMPI for the Structure and Dynamics of Matter, Hamburg

Dynamical control of structural orderCoherent excitation of lattice vibrations has emerged as a powerful approach to dynamicallycontrol functional material properties. In this talk, I will present our recent work on using nonlinearphononics—a mechanism that enables the selective displacement of specific lattice vibrations—tomanipulate structural functionalities with light [1,2]. In particular, I will discuss how this approachenables the ultrafast control of chirality [3] and ferroaxial order [4], offering new pathways to tailorsymmetry and drive phase transitions in solids on demand.

[1] Först, et al. Nature Physics 7 (2011): 854-856.[2] Disa, et al. Nature Physics 17 (2021): 611-618.[3] Zeng, et al. Science 387.6732 (2025): 431-436.[4] Zeng, et al. Science 390.6769 (2025): 195-198.

Venue: RUN Auditorium

RTG Seminar: Yiqi Fang
2026-05-21 13:00 - 14:00
Shaping electron dynamics with structured light

FAU Erlangen, Institute of Laser Physics

Laser-excited electron motions allow the investigation of fundamental physical phenomena with unprecedented resolution in time, space and energy. Structured light offers new opportunities to tailor and control the optical response of materials, far beyond the ability of conventional linearly or circularly polarized light. In this talk, I will show the physics and application of structured light when it interacts with bound electrons in atoms as well as when it interacts with electron pulses in free space.

Venue: RUN.0.35

RTG Colloquium: Thomas Taubner
2026-05-22 14:00 - 15:30
Infrared near-field spectroscopy of few-layer graphene

RWTH Aachen, Germany

Infrared scattering-type scanning-near-field optical microscopy (s-SNOM) enables the imaging of nanostructures with sub-diffraction resolution by elastic light scattering at a sharp tip. s-SNOM also boosted the field of 2D materials by enabling real-space imaging of plasmon- or phonon polaritons, e.g., in graphene and hexagonal Boron Nitride (hBN), respectively. Polariton imaging with s-SNOM has allowed for indirectly mapping (grain) boundaries and (stacking) defects in fewlayer Graphene (FLG) via polariton reflection.Here, I will present how spectroscopic IR s-SNOM is able to determine the local stacking order at nanoscale resolution not only of bare few-layer graphene, but also when it is encapsulated below hBN layers. I will explain the contrast mechanisms, mainly based on the characteristic and stacking-dependent interband transitions of FLG, for bilayer graphene, trilayer (TLG) graphene and tetralayer graphene (4LG). We retrieve and reconstruct these characteristic complex optical conductivity resonances from the amplitude and phase of the scattered light, which e.g. allow for the unambiguous assignment of previously undetected ABCB domains in 4LG.Coupling the (stacking-dependent) FLG with phonon polaritons in a hBN TLG heterostructure also leads to coupled polaritons (hyperbolic phonon plasmon polaritons). We explore how they allow for super-resolution imaging of subdiffraction-sized defects in graphene through the hBN cover layer via the so-called hyperlensing effect. Furthermore, we show how resonators for polaritons in 2D materials like hBN can be easily fabricated and optically reconfigured using Phase-Change Materials.

Venue: RUN Auditorium

RTG Colloquium: Gabriele Kaminski Schierle & Clemens Kaminski
2026-06-11 14:00 - 16:00
Biological imaging at the nanoscale

Clemens F. Kaminski, University of Cambridge

The advent of optical super‑resolution imaging together with the ability to label specific cellular components with fluorescent markers has ushered in a revolution in our mechanistic understanding of biological processes. In this presentation, I will provide an overview of current methods used to obtain nanoscale insights into the molecular machinery that supports life at the subcellular level. I will present approaches for tracking protein interactions, using single‑molecule localisation microscopy as well as indirect techniques such as fluorescence lifetime imaging microscopy. I will then discuss methods based on structured illumination microscopy, which enable dynamic interrogation of cellular machinery including lysosomes and the endoplasmic reticulum. Finally, I will offer an outlook on emerging trends and how machine learning is transforming our field.

Coffee break & discussion

Beyond Alzheimer’s: conserved lysosomal dyshomeostasis as a driver of synaptic dysfunction across neurodegenerative proteopathies

Gabriele S. Kaminski Schierle, University of Cambridge

While scientists know that in Alzheimer’s disease, lysosomes (the cell’s “trash cans”) clump together and lose their acidity, they didn’t know if this happens in all neurodegenerative diseases.This study found that this “trash can” breakdown actually happens across many diseases, including ALS, Parkinson’s, and Frontotemporal Dementia. Instead of being spread out normally to clean the whole cell, the lysosomes clump tightly around the cell’s centre.By tracking cell electricity and layout, the researchers discovered that this clumping severely damages brain signalling. Because the lysosomes are stuck in the centre, they can’t reach the distant outer branches of the brain cells to clear out old, broken proteins. This causes waste to build up and shorts out communication between neurons.Ultimately, this suggests that fixing where lysosomes sit and restoring their acidity could act as a single, powerful treatment for multiple brain diseases.

Venue: RUN Auditorium

RTG Seminar: Prasana Kumar Sahoo
2026-06-18 14:00 - 15:00
Engineering excitons in 2D lateral heterostructures for reconfigurable devices

Quantum Materials & Device Research Lab (QMDrL), Materials Science Centre,Indian Institute of Technology Kharagpur, India

Two-dimensional semiconductor lateral heterostructures (LHS) provide atomically sharp 1D interfaces for controlling charge carriers, excitons, and light. I will present scalable growth of seamless TMD LHS, exhibiting tunable PN junctions, electroluminescence, excitonic transistor operation, and reversible photoconductivity. These materials offer a versatile platform for quantum photonics, exciton-based devices, and low-dimensional quantum systems.

Venue: RUN 0.34

RTG Colloquium: Alice Kunin
2026-06-19 14:00 - 15:00
High-performance time-resolved photoemission experiments of quantum materials

Princeton University

I will discuss our work coupling MHz, kW light sources with momentum microscopy to enable efficient time- and angle-resolved photoemission (tr-ARPES) studies. I will first examine the dynamics of intra- and interlayer excitons in twisted van der Waals heterobilayers. I will then discuss our current work on a new spectrometer to probe ultrafast surface photochemistry in situ with the extension of tr-ARPES beyond ultrahigh vacuum towards more realistic chemical environments.

Venue: RUN Auditorium

RTG Colloquium: Bruno Schuler
2026-07-03 14:00 - 15:00
Empa, Switzerland

Venue: RUN Auditorium
