Researchers observe ultrafast processes of single molecules for the first time
(PHYSorg.com Physics)

Markus Koch, head of the research group Femtosecond Dynamics at the Institute of Experimental Physics at TU Graz, and his team develop new methods for time-resolved femtosecond laser spectroscopy to investigate ultrafast processes in molecular systems. In 2018 the group demonstrated for the first time that photo-induced processes can be observed inside a helium nanodroplet, a nanometer-sized droplet of superfluid helium that serves as a quantum solvent. For their investigations, the researchers placed a single indium atom inside the droplet and analysed the reaction of the system with the pump-probe principle. The atom was excited with an ultrashort laser pulse, triggering the rearrangement of the helium environment within femtoseconds (10-15 seconds). A time-delayed second laser pulse probed this development and provided information on the behavior of the system.