THz Structural Dynamics
THz Structural Dynamics
Research Group Sebastian Maehrlein
Research Group Sebastian Maehrlein


Welcome to the THz Structural Dynamics group …

    We, the team of the new THz structural dynamics group, are obviously fascinated about structural dynamics. Why that? Material properties and chemical reactions are fundamentally determined by the spatial arrangement of atoms, ions or molecules. If we can modulate or change this spatial structure on ultrafast time scales, we can control properties on demand or even discover new material features. For this, we generate highly intense and phase stable laser pulses in the THz and midinfrared spectral range, which enable us to coherently drive specific structural dynamics on their fundamental time and energy scales. Furthermore, we want to explore tailored lattice trajectories, which may help to steer solids into hidden states. Currently, we are focusing on phonon anharmonicities, molecular orientations in solids and dynamically disordered systems.

    Feel free to roam through our fields of research, follow us @sfmaehrlein | or contact us any time. We acknowledge additional external funding from …

    Latest news …

    New Publication - Nonlinear THz Control of the Lead Halide Perovskite Lattice
    May 2023
    Max’ and Marie’s exciting work is now published as a research article in Science Advances. Therein we demonstrate how to obtain coherent control over specific lattice modes in lead halide perovskites. We find nonlinear excitation pathways using intense single cycle THz pulses to dynamically steer the twist angles of the inorganic cage, which govern fundamental optoelectronic properties, dynamic disorder and structural phase transitions. Full study open access here:

    M. Frenzel, M. Cherasse et al., “Nonlinear THz Control of the Lead Halide Perovskite Lattice”, Science Adv. (2023)
    First PhD Graduation
    Dec 2022
    We are very proud of Marie Cherasse who successfully graduated with the title Docteur de l’Institut Polytechnique de Paris from Ecole Polytechnique Paris with her work on Ultrafast Dynamics in Hybrid Perovskites. Big congrats and best wishes for your next steps. We’ll miss you here at FHI, Marie!
    Marie receives French L’Oréal UNESCO Award for Women in Science
    Oct 2022
    BIG Congratulations to our PhD student Marie Cherasse who received the highly competitive French L’Oréal UNESCO Award for Women in Science. Thanks for using your science communication talent to also discuss the often-neglected role of diversity in science, Marie!
    See further news coverage by Forbes, l’X, and .. [more...]
    Sebastian receives prestigious Emmy Noether grant
    Jul 2022
    BREAKING NEWS: In October, we’ll be converting to an independent Emmy Noether research group funded by the German Research Foundation (DFG) for the next 6 years. This will not only allow us to further grow our group, ambitions and labs. We will deepen our research focus on actively steering lattice angular momentum in solids for ultrafast control of material properties. Apply here for a fully funded PhD position. [more...]
    New group member - Joanna
    Apr 2022
    Our group is now approaching a real dream team: Welcoming Joanna Urban as our new Postdoc adds one of the last missing puzzle pieces! From her previous research positions in France, Joanna brings exceptional expertise in spectroscopy and physics of layered materials for a variety of methods.

    What a pleasure to have you with us, Joanna!

    Joanna’s fun fact: She is clearly our group’s language guru; try to speak a number of European languages with her!
    New Publication - First 2D-HYPE Publication
    Mar 2022
    Congratulations to our PhD student Marie Cherasse for her first first-author publication. In the labs of Luca Perfetti she discovered via time resolved two-photon photoemission (2PPE) that the surface charge regions of hybrid organic-inorganic lead halide perovskites serve as a perfect test ground to probe the screening capabilities of their organic cations. We found strikingly different dynamics depending on the orientational degrees of freedom of the A-site cation in different crystallographic phases.

    M. Cherasse et. al., “Electron Dynamics in Hybrid Perovskites Reveal the Role of Organic Cations on the Screening of Local Charges”, ACS Nano Lett. (2022)
    New group member - Dorothée
    Feb 2022
    We are more than happy to welcome our newest group Member Dorothée Mader, who will be a joint PhD student together with the Lattice Dynamics group. Within the Max Planck-Radboud Center for IR-FEL spectroscopy she will work on phonon-driven switching of ferroic states. Welkom, Dory!

    Dorothée’s fun fact: She not only masters chiral distortions on the macroscopic, but also on the human length scale.
    Start of our ANR-DFG research consortium "2D-HYPE"
    Jan 2022
    We are extremely excited that our French-German research project on “Correlated electron and structural dynamics in quasi-2D HYbrid PErovskites” (2D-HYPE) got funded by ANR and DFG. Together with our French partners Luca Perfetti and Emmanuelle Deleporte, we will use complementary tools of time-resolved ARPES and nonlinear THz spectroscopy to investigate the crucial interplay of lattice, ionic and electronic degrees of freedom in this emerging class two-dimensional lead halide perovskite semiconductors.

    Dynamique des électrons et du réseaux dans les perovskites hybrides et quasi-2D ? …stay tuned
    New group member - Michael
    Aug 2021
    Very warm welcome to Michael Spencer, who joined our group as a PostDoc! Coming all the way from New York City, Michael brings his expertise in cavity polaritons, lasing of perovskites, and polarization resolved photoluminescence. What a catch!

    We are happy to have you with us, Michael!   

    Michael’s fun fact: Michael belongs to a unique species of scientists, perfectly fit to both urban and rural habitats.
    Part of the new the Max Planck Center
    Jul 2021
    We are excited to be part of the newly founded Max Planck-Radboud University Research Center for Infrared Free Electron Laser Spectroscopy! The Center enhances the joint research capabilities of the Max Planck Society and Radboud University (Nijmegen, NL) based on their unique Free Electron Laser instrumentation. We are proud to contribute with our complementary tabletop high-field THz/MIR lab in a joint project to seek for ultrafast, but permanent, switching of material properties via phonons. Join for a PhD position!