Ultrafast field-resolved electron microscopy

When light is absorbed at a solid surface, not much more than the outcome is known: Charges are separated and electric fields are excited.

How this fundamental process happens on the attosecond time and nanometer length scale remains elusive due to the lack of a single method with sufficient resolution.

This not only prevents a profound theoretical description of non-equilibrium charge dynamics in solids, but also hinders technological applications towards nano-optical devices.

This project’s goal is to develop the necessary tools and investigate ultrafast electronic processes happening in single nanostructures.

It aims at advancing photoemission electron microscopy to the attosecond time scale to resolve optical fields both spatially and temporally. To this end, we perform attosecond streaking experiments with pairs of attosecond pulses on individual nanostructures.

The project is an interdisciplinary effort bringing nanostructures and surface science together with state-of-the-art laser technology and attosecond time-resolved methods.

It is scheduled for four years, first proofing the feasibility, then upgrading the high-order harmonic generation to a long driving wavelength of 2 µm and finally resolving ultrafast charge dynamics and controlling them with the instantaneous optical field.

This will provide direct insight into strong-field driven processes on the nanoscale, highly relevant for future optical transistors, solar cells and ultrafast electron sources.