Time-resolved studies of ultrafast electronic processes in two-dimensional solids in the strongly non-thermal regime

• Applicant: Professor Dr. Michael Bauer
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2017 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 389191527

Within the proposed project we aim for studying the dynamics of primary electronic processes in model-type two-dimensional material systems during and shortly after excitation by an intense sub-7 femtosecond laser pulse, i.e. in the strongly non-thermal regime. Within the studies we will focus on graphitic materials (graphene and graphite) as well as the semiconducting transition metal dichalcogenide MoTe2. In the case of the two graphitic systems we aim for studying in detail the impact of carrier-carrier interaction and carrier-phonon interaction onto the internal thermalization of the electron gas within the first 50 fs after optical excitation. Regarding the transition metal dichalcogenide MoTe2 the project will focus on the dynamics of band renormalization effects and a conspicuous Mott-transition, both associated with the built-up of screening as the conduction band is transiently populated by an intense excitation pulses. The studies will be conducted with a specifically designed time- and angle-resolved photoemission experiment capable of probing ultrafast processes with a time resolution < 10 fs and near the Fourier-limit. These specifications will enable us to directly monitor the imprint of the characteristic energy scales of the involved electronic, phononic and excitonic degrees of freedom onto the transient changes of the electronic structure on the extremely short timescales relevant for the addressed problems.

• DFG Programme: Research Grants