Time-Resolved Spectroscopy of Strong-Field-Driven Solids

ended

Intense short light pulses have recently been used to manipulate the optical and electronic properties of solids, promising applications for future ultrafast optoelectronics devices. However, the origin of these strong-field processes has triggered an intense debate. To identify the main contributing physical processes and their dependence on the properties of the system, it is essential to access these strong-field dynamics in their sub-femtosecond time scale. Motivated by these very recent advances, I will determine strong-field dynamics in several classes of solids, and show how time-resolved spectroscopy can be used to access the response of the medium to intense fields. I will perform numerical simulations based on time-dependent density-functional theory, benefiting from the expertise of Prof. Madsen's group in developing numerical methods for strong-field physics also in complex many-body systems. This will allow me to explore strong-field dynamics in classes of solids which are especially promising for ultrafast applications, as identified by previous findings in high-order harmonic generation. In addition, I will take advantage of my previous analytical work in atoms and molecules, also in collaboration with experimental groups, to solve the semiconductor Bloch equations and develop associated analytical techniques, in order to interpret the numerical results. Training in numerical methods will be reinforced by a secondment in the group of Prof. Bauer, while constant interactions with experimentalists will ensure the identification of the most suitable systems, and exploitation of the results. By identifying key spectroscopy features and relating them to the underlying strong-field dynamics in solids, this work will guide near-future experiments in time-resolved spectroscopy of condensed-matter systems, and facilitate the design of suitable materials for applications in the very recently established field of multi-petahertz optoelectronics.