The Fritz Haber Institute (FHI) in Berlin is one of the oldest and highly renowned research institutes within the Max Planck Society, Germany's most successful scientific organization. At the FHI, researchers from all over the world are engaged in basic research in the fields of physics and chemistry at interfaces, catalysis research, and molecular physics. 

The Department of Physical Chemistry  focusses on the dynamics of elementary processes in solids and at surfaces, in particular, ultrafast dynamics of electronic and lattice excitations, electron-phonon coupling, interfacial charge transfer, spin dynamics, as well as spectro-microscopy and light-matter interaction at the nanoscale.

Within the Department of Physical Chemistry, the Lattice Dynamics group, is currently looking for a 

3-year postdoc (m/f/d) for infrared imaging and spectroscopy using free-electron lasers.

Our group uses the in-house infrared free-electron laser (FHI-FEL) as well as external FEL user-facilities (FELBE, FELIX) to perform advanced imaging and spectroscopy of condensed phase systems and interfaces from the mid- and far-infrared into the THz. Our techniques range from direct spectroscopic imaging in the infrared to subdiffractional imaging using nonlinear optical sum-frequency approaches or tip-based near-field imaging. Additionally, we also perform momentum space spectroscopy and momentum space imaging to map the dispersion of evanescent modes. Finally, we also currently established time-resolved infrared-THz pump-probe spectroscopy using the newly commissioned two-color operation of the FHI-FEL.

Using this portfolio of advanced methodology, we study a wide range of interface and thin film phenomena in condensed phase systems. While our efforts have largely focused on phonon polaritons in anisotropic polar crystals and van der Waals (hetero-)structures, we also currently expand on investigating domains and domain walls in ferroelectric materials, lattice anharmonicities in battery and energy materials, or even chemical reactions at liquid-liquid interfaces. Relevant recent publications documenting the scientific profile of the group include:

Kowalski et al., Ultraconfined THz Phonon Polaritons in Hafnium Dichalcogenides, arXiv:2502.09909 (2025). 
Carini et al., Surface Phonon Polariton Ellipsometry, ACS Photonics 12, 792 (2025).
Niemann et al., Spectroscopic and Interferometric Sum-Frequency Imaging of Strongly Coupled Phonon Polaritons in SiC Metasurfaces Adv. Materials 36, 2312507(2024).  
Galiffi et al., Extreme light confinement and control in low-symmetry phonon-polaritonic crystals, Nat. Rev. Mat. 9, 9 (2024). 
Passler, et al., Hyperbolic shear polaritons in low-symmetry crystals, Nature 602, 595 (2022).

The offered senior Postdoc position has a duration of 3 years and is accompanied by an individualized Max-Planck training and mentoring program as well as career planning assistance through the Planck Academy. This specialized program specifically addresses excellent and highly motivated scientists in their early career phase who want to make an important career step by developing their individual research profile. We therefore encourage applicants to propose and develop their own research projects within the group’s capabilities, and offer the opportunity to conduct these research projects with a large degree of freedom. Applicants should hold a Ph.D. in physics, chemistry, materials science or related fields. A broad knowledge in solid state physics and light matter interaction would be highly beneficial as well as experimental experience in one or more of these areas:

• Nonlinear spectroscopy
• Pump-probe spectroscopy
• THz spectroscopy
• Optical microscopy
• Near-field microscopy

Moreover, candidates are expected to have

• Collaborative spirit and ability to work in an international research environment
• Affinity for performing complex experiments with a high drive to solve scientific and practical/instrumental challenges.

Your application should include:

• Motivation letter
• CV
• Contact details of at least two academic references

The FHI strives for gender equality and diversity. We welcome applications from all backgrounds. The Max Planck Society is committed to increasing the number of individuals with disabilities in its workforce and therefore encourages applications from such qualified individuals. Furthermore, the Max Planck Society seeks to increase gender diversity in research and therefore explicitly encourages women and non-binary people to apply.

For more information please contact:

Dr. Alex Paarmann, e-mail: alexander.paarmann@fhi.mpg.de,

Fritz Haber Institute of the Max Planck Society, Department of Physical Chemistry, 14195 Berlin