Femtosecond Dynamics - Koch Group

We investigate how light interacts with matter. In particular we are interested in ultrafast processes such as nuclear and electronic dynamics, or the transfer of energy and charges, which we study in real time with femtosecond laser pulses. A repertoire of experimental approaches allows us to observe these primary processes in various different systems under diverse environmental conditions: Form isolated molecules in gas phase, over molecular clusters inside superfluid helium nanodroplets, to nanostructured solids.

Open Positions

Master’s Thesis: Molecules in a Quantum Solvent

Recently, we discovered that the vibrational motion of molecules is only marginally influenced when they are solvated in a quantum solvent (superfluid helium), in strong contrast to conventional solvents (Phys Rev Lett 124, 115301). Do you want to know how many conventional solvent molecules it takes to restore full damping? – we too, join the team and perform the experiment! (2640 € compensation, contact markus.kochnoSpam@tugraz.at)

Master’s Thesis: Ultrafast Microscope

Our new ultrafast microscope allows us to can observe ultrafast processes in nano- and microstructured samples in space and time, with 50 fs temporal and 1 µm spatial resolution. The next development step, which is the goal of this thesis, is the implementation of “spatially separated pump-probe” (left figure below), which will allow to image charge carrier motion and energy flow in these systems. The figure below depicts, as an example, the electron motion in Si nanowires (2640 € compensation, contact markus.kochnoSpam@tugraz.at).

Master's Thesis: Solar Energy Harvesting - Ultrafast Processes in Sunlight-driven H2 Production from Water.

Apply femtosecond laser spectroscopy to investigate ultrafast charge transfer processes involved in photo-induced water splitting. This process, which has been predicted by theory but still awaits experimental verification, might establish a new route towards the conversion of solar energy into chemical energy (2640 € compensation, contact markus.kochnoSpam@tugraz.at).

Latest News

2021-07-09: Nature Communications paper. First demonstration that electrons in liquids can be accelerated with laser pulses. Nat Commun 12, 4204

2020-12-10: Bernhard Thaler receives the Award of Excellence from the Austrian Ministry of Education, Science and Research for his PhD Thesis on ultrafast dnamics in He droplets – congratulations Bernhard!

2020-05-01: New Project starts. Femtosecond photochemistry in a quantum solvent, funded by the FWF (P33166), sets out to explore the opportunities and limits of femtosecond specroscopy inside He droplets. - See, He drops can pick up money.

2020-03-20: PRL paper
Long-Lived Nuclear Coherences inside Helium Nanodroplets: Our observation of a  nuclear wave packet motion of molecules inside superfluid He nanodroplets is a big step towards ultrafast photochemistry inside these nano-cryo-containers. We discover that the quantum fluid is a great solvent with extremely low influence on the molecule.
Phys Rev Lett 124, 115301 (2020) | full text
Focus stories: APS Physics magazine | AIP Inside Science
Press coverage: | ChemEurope| Chemie.DE | APA | Der Standard | TU Graz

2020-01-10: JPCL paper
Progress in the understanding of energy transfer in a molecule: Through a collaboration with the González group we obtain detailled insight into the population transfer in acetone.
J. Phys. Chem. Lett. 11, 1443  (2020)
press coverage: ChemEuropeChemie.DE | EurekAlert! | ScienceDaily| PhysOrg | Der Standard | Die Presse

All images © TU Graz/Institute of Experimental Physics