Periodic Reporting for period 4 - AEDMOS (Attosecond Electron Dynamics in MOlecular Systems)
Período documentado: 2019-11-01 hasta 2020-04-30
Advanced insight into ever smaller structures of matter and their ever faster dynamics hold promise for pushing the frontiers of many fields in science and technology. Time-domain investigations of ultrafast microscopic processes are most successfully carried out by pump/probe experiments. Intense waveform-controlled few-cycle near-infrared laser pulses combined with isolated sub-femtosecond XUV (extreme UV) pulses have made possible direct access to electron motion on the atomic scale. These tools along with the techniques of laser-field-controlled XUV photoemission (“attosecond streaking”) and ultrafast UV-pump/XUV-probe spectroscopy have permitted real-time observation of electronic motion in experiments performed on atoms in the gas phase and of electronic transport processes in solids.
The purpose of this project is to to get insight into intra- and inter-molecular electron dynamics by extending attosecond spectroscopy to these processes. AEDMOS will allow control and real-time observation of a wide range of hyperfast fundamental processes directly on their natural, i.e. attosecond (1 as = 10-18 s) time scale in molecules and molecular structures. In previous work we have successfully developed attosecond tools and techniques. By combining them with our experience in UHV technology and target preparation in a new beamline to be created in the framework of this project, we aim at investigating charge migration and transport in supramolecular assemblies, ultrafast electron dynamics in photocatalysis and dynamics of electron correlation in high-TC superconductors. These dynamics – of electronic excitation, exciton formation, relaxation, electron correlation and wave packet motion – are of broad scientific interest reaching from biomedicine to chemistry and physics and are pertinent to the development of many modern technologies including molecular electronics, optoelectronics, photovoltaics, light-to-chemical energy conversion and lossless energy transfer.
The purpose of this project is to to get insight into intra- and inter-molecular electron dynamics by extending attosecond spectroscopy to these processes. AEDMOS will allow control and real-time observation of a wide range of hyperfast fundamental processes directly on their natural, i.e. attosecond (1 as = 10-18 s) time scale in molecules and molecular structures. In previous work we have successfully developed attosecond tools and techniques. By combining them with our experience in UHV technology and target preparation in a new beamline to be created in the framework of this project, we aim at investigating charge migration and transport in supramolecular assemblies, ultrafast electron dynamics in photocatalysis and dynamics of electron correlation in high-TC superconductors. These dynamics – of electronic excitation, exciton formation, relaxation, electron correlation and wave packet motion – are of broad scientific interest reaching from biomedicine to chemistry and physics and are pertinent to the development of many modern technologies including molecular electronics, optoelectronics, photovoltaics, light-to-chemical energy conversion and lossless energy transfer.
In this project, a laser system was installed in a new laboratory and upgraded with a booster system, which lead to pulse parameters of 800nm / 3 fs / 4 kHz / 2 mJ. This is now state of the art, not many of these laser systems are available on the world. As it was planned, the attosecond beamline was built up in the lab next to the laser system and connected to the laser by a tube leading through the wall. The experimental chamber was manufactured, set up and tested. First streaking experiments were performed in the gas phase. The beamline operates perfectly. we developed a new setup for UV pulse generation based on achromatic frequency doubling. Few-cycle UV-pulses with unprecedented pulse energy are available.
To test the beamline we made measurements in the gas phase (M. Ossiander et al, Nature Physics doi:10.1038/nphys3941 (2017)) and on layered systems (M. Ossiander et al., Nature 561, 374 (2018). Many further gexperiments have been performed on verious samples giving insight into attosecond electron dynamics in solids, layered systems, molecules on surfaces.
We established many collaborations for target preparation Prof. Kisch, Erlangen, Germany; Prof. Domen, Japan), simulations (Prof. Ebert, LMU, Germany; Prof. Lemell, TU Vienna, Austria), target characterizytion (Prof. Schiffrin, Monash University, Australia) and evaluation software: We implemented a new method for streaking evaluation based on deep learning algorithms together with the group of Prof. Cremers, IT, TUM. Also, We developed a new evaluation method for streaking method by using a ptychographic ansatz.
To test the beamline we made measurements in the gas phase (M. Ossiander et al, Nature Physics doi:10.1038/nphys3941 (2017)) and on layered systems (M. Ossiander et al., Nature 561, 374 (2018). Many further gexperiments have been performed on verious samples giving insight into attosecond electron dynamics in solids, layered systems, molecules on surfaces.
We established many collaborations for target preparation Prof. Kisch, Erlangen, Germany; Prof. Domen, Japan), simulations (Prof. Ebert, LMU, Germany; Prof. Lemell, TU Vienna, Austria), target characterizytion (Prof. Schiffrin, Monash University, Australia) and evaluation software: We implemented a new method for streaking evaluation based on deep learning algorithms together with the group of Prof. Cremers, IT, TUM. Also, We developed a new evaluation method for streaking method by using a ptychographic ansatz.
The attosecond beamline that was set up is world class and permits experiments on attosecond electron dynamics. These dynamics – of electronic excitation, exciton formation, relaxation, electron correlation and wave packet motion – are of broad scientific interest reaching from biomedicine to chemistry and physics and are pertinent to the development of many modern technologies including molecular electronics, optoelectronics, photovoltaics, light-to-chemical energy conversion and lossless energy transfer.