When light falls on a solid, in many cases the light is absorbed and this results in the energetic excitation of charge carriers in the material. The solar cells on our roofs work in this way. But what happens when the irradiation with light becomes so intense that it is no longer the (time-averaged) light intensity that dominates the charge carrier dynamics, but the electric field of the light? Suddenly it becomes possible to control the charge carriers directly with light on the attosecond time scale. If we remember that in our current smartphones it is ultimately only electric fields that "push" the charge carriers around, we can imagine what would be possible with light, which switches many orders of magnitude faster.

On this time scale, however, somewhat different laws apply than those we are familiar with from our daily lives. Quantum effects play an important role, also due to the simultaneously small length scale in the (sub-) nanometre range. In the Attosecond Microscopy working group, we are investigating how we can visualise charge carriers ultrafast and on the smallest spatial scales. We aim to identify new ways of controlling charge carriers before they lose their fixed phase relationship with the light wave that drives them due to incoherent scattering processes.

Contact:

Attosecond Microscopy Group
Dr Jan Vogelsang