• Ultrafast Dynamics in Condensed Matter

Welcome to the UDKM group website

We investigate coherent and incoherent non-equilibrium phenomena at the nanoscale initiated by various external stimuli, e.g. light and electromagnetic pulses. While incoherent processes transport heat and charges and may drive phase transitions and chemical reactions, coherent dynamics range from strain- and spin waves to strong coupling in exciton-plasmon systems.

Our focus is on a time-domain description of transporting and transforming energy among various excitations of matter. Transient strain and lattice dynamics in general are central observables in solids that are often connected and thus sensitive to other excitations such as hot electrons, lattice vibrations (phonons) and spin waves, electron-and phonon excitations, as well as  the latent heat of phase transitions. We aim at controlling strain waves in order to advance the field of nonlinear phononics and identify means of strain-assisted manipulation of magnetic and ferroelectric order. Polaritons, in particular plasmons, couple macroscopic light fields into the nanoworld, acting as an antenna for the chemical, electronic, magnetic or phononic excitations.

Typical research questions of the group involve ultrafast excitations, electron-phonon interaction, strain and heat as a driver of or sensor for ultrafast magnetism, ferroelectric switching and chemical reactions.

We attempt to create a special perspective on these phenomena by combining our experimental workhorses, which are ultrafast versions of x-ray diffraction, magneto-optics, transient absorption and reflection as well as time-resolved Raman scattering. We synthesize plasmonic nanostructures such as nanorods or nanostars embedded in soft condensed matter, e.g. nanolayered polyelectrolytes, whereas solid nanostructures are provided by our collaboration partners.

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You've succesfully made your way through the WWW to our new webpage! :)

Welcome Rekikua!

We warmly welcome our new PhD student Rekikua! She will explore the concept of laser-assisted switching in ferroelectric thin film devices.

Welcome Alexander!

We warmly welcome our new Bachelor student Alexander! He will help us improving the sample holder and environment for the laser-assisted ferroelectric switching experiments in our University and synchrotron labs. He will also perform related experiments.

Stressful magnets!

Max' paper on the role of spin stress in laser-excited magnetic oxide SrRuO3 is available fresh from the press!

Novel active x-ray optics!

A new concept for efficient gating of x-ray pulses at synchrotrons and FELs using laser-excited surface acoustic waves has been published!

Reciprocal space rocks! :)

Check out our brand new publication on time efficient x-ray diffraction methods!