The Fritz Haber Institute (FHI) in Berlin is one of the oldest and most renowned research institutes within the Max Planck Society (MPG), 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 and surfaces, 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, surface reactions, as well as light-matter interaction at the nanoscale.

The newly founded Max Planck-Radboud University Center ( enhances the joint research capabilities of the Max Planck Society and Radboud University (Nijmegen, NL) based on their unique Free Electron Laser (FEL) instrumentation. Our state of the art FELs allow for intense and nonlinear infrared (IR) spectroscopy with applications ranging from biomedicine to chemistry and materials science to astrophysics.

Within the projects of the new Center, the Lattice Dynamics (LD) ( and THz Structural Dynamics (TSD) ( groups in the Department of Physical Chemistry offer a joint

PhD Position: Understanding Phonon-Driven Ultrafast Switching of Macroscopically Ordered Solids

This position will offer the unique opportunity of combing the ultrafast time- and phase-resolution of the tabletop high-field THz/mid-IR labs (TSD group) with the complementary spatial- and frequency-resolved capabilities of the FHI-FEL-based labs (LD group). The work of the TSD group mainly targets the question how structural dynamics (lattice vibrations, molecular rotations, etc.) can be harnessed and controlled to steer material properties on ultrafast time scales or to discover novel transient states of matter. Therefore, highly intense, few-cycle terahertz (THz) to mid-IR pulses are combined with a broad range of nonlinear and phase-resolved probing techniques with femtosecond time-resolution. The general research interest of the LD group is centered around optical phonons in polar dielectric crystals, their surfaces, hetero- and nanostructures. Nanophotonic systems, e.g. based on phonon polaritons, are investigated with various linear and nonlinear IR spectroscopy techniques, employing the FHI-FEL as a unique intense and tunable infrared light source. Recently, this arsenal has been extended by spatial resolution from infrared-visible sum-frequency generation super-resolution microscopy.

Topics of the research:

Within the Center’s project “Shaken, not stirred: How phonons can switch the order in ferroics”, we will investigate how vibrational resonances of solids can be employed to trigger ultrafast, but permanent, switching of ordered material properties, specifically magnetic or electric properties. To achieve and microscopically understand such non-volatile control of the responsible order parameters, the project will explore the role of phonons in dynamic symmetry breaking, their anharmonic coupling and their general impact on the ferroelectric or magnetic order. The corresponding experiments will be developed and conducted at existing setups for time-domain nonlinear THz/mid-IR spectroscopy and FEL-based frequency-domain nonlinear microscopy. The project’s highly anticipated insights may provide novel handles for energy efficient data storage or alternative computing platforms in future.

The fully-funded PhD position is initially limited to 3 years, with a possibility for extension. The PhD student will be based at FHI in Berlin. The willingness to spend about 20% of the time at the partner group in the Netherlands is anticipated.

Your profile:

Applicants should hold an excellent Master’s degree or equivalent in physics, chemistry, material science or related fields. Experimental experience in one or more of these areas is highly beneficial:
• Nonlinear spectroscopy
• Pump-probe spectroscopy
• THz spectroscopy
• Optical microscopy
• Coherent Phonons

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

Applications for this position are only accepted via our online application portal. Closing date: Applications will be accepted until Oct 31st, 2021. We thank all applicants for their interest; however, only those individuals selected for an interview will be contacted.

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. Sebastian F. Maehrlein, e-mail: or
Dr. Alex Paarmann, e-mail:,
Fritz-Haber-Institut der Max-Planck-Gesellschaft, Department of Physical Chemistry, 14195 Berlin

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