Peering into the inner parts of materials

Over the past decade, attosecond physics prompted extensive theoretical efforts to provide numerical predictions for models regarding light–matter interaction and electron dynamics inside atoms. So far, investigations have been conducted on atoms, molecules and the surfaces of solid samples. However, the EU-funded project 'Attosecond electron processes in solids' (ATTOTRON) seeks to use attosecond radiation to expose the dynamic properties of bulk materials.

Much like microwave radiation, near-infrared and optical fields can significantly alter the physical properties of wideband materials such as dielectric used in semiconductor technologies. In particular, ultrashort laser pulses allow dielectric damage-free exposure and significant modifications in their electronic system. Furthermore, such high- and temporally confined fields allow turning a dielectric from an insulator to a conductor.

ATTOTRON offers the possibility to manipulate the dielectric electronic structure and its ability to be polarised with sub-femtosecond near-infrared laser radiation. Its studies into narrow-gap semiconductors promise to deliver in-depth understanding of the electron visible excitation dynamics and the ultrafast coupling of electronic and nuclear kinetics. A theoretical framework for data analysis recorded in the newly developed experimental scheme is under development in collaboration with theorists.

Femtosecond electronic population transfer in solids is the foundation of modern silicon-based technology and thus the cornerstone of machine intelligence and communication technologies. ATTOTRON studies into controlling and observing the electron temporal behaviour should offer significant insight into the band structures and carrier dynamics in bulk materials. Findings regarding ultrafast electron dynamics in silicon dioxide have been published in a peer-reviewed journal.