Periodic Reporting for period 1 - TiMoleS (Time-resolved Molecular Selfies (TiMoleS): Visualising molecular dynamics in real time)
Okres sprawozdawczy: 2020-09-01 do 2022-08-31
A chemical reaction is often an unsolved maze game: we know where it starts and ends, but the path followed is a question that remains. Time-resolved imaging of molecular dynamics, therefore, is of primary interest. To solve aforementioned, we miss a sub-Ångström spatial and sub-femtosecond temporal resolution imaging scheme that can probe both nuclei and electrons. In this project TiMoleS, I propose to lay the theoretical and conceptual groundwork for such an imaging tool that can monitor molecular reaction and accompanying electron dynamics. This will be done by letting the target molecule to image by itself via two coexisting strong field processes termed laser-induced electron diffraction and laser-induced electronholography. I intend to use these processes in a complementary way to image nuclear dynamics as well as the electron cloud evolution. Through well-organized work packages for rigorous theoretical and computational developments and by collaborating with specialists of the domain, I propose to surmount difficulties linked with these processes to realize ultrafast imaging. Timoles will develop analytical models, numerical codes and optimal control schemes to come up with rather general imaging method for AB/AB2 molecules. It will give an excellent insight into photochemical reactions, various reaction pathways and control over reaction
dynamics, like enhancing the desired reaction or even to prevent an undesired process. These control scheme developed for generalized probing of the dynamics will also accelerate our attempts to design ultrashort lasers in higher frequencies.
dynamics, like enhancing the desired reaction or even to prevent an undesired process. These control scheme developed for generalized probing of the dynamics will also accelerate our attempts to design ultrashort lasers in higher frequencies.
The work has focused on studying the effect of many-electron effects in relation to the time-resolved strong-field physics processes described in project description of the grant agreement. This work has been performed along two avenues. On the one hand, many-electron polarization effects have been included in the fundamental strong-field ionization process. On the other hand, an approach that considers the many-electron polarization effect in the nonlinear, high-order harmonic generation process has been explored.
The imaging of electronic and molecular dynamics in real time is believed to be an important tool to gain more insight into the microscopic motion of atoms and molecules. Such insight could pave the way for new control schemes and associated new technologies. For example, one could imagine control of dynamics at optical frequencies that could lead to the development of petaherz electronics operating on a time scale several orders of magnitude faster than the present-day limit. Such possibilities would of course have large impact on computer power and hence the broader society.
In connection time-resolved dynamics and possibilities, it is a challenge to deal with the fact that the electrons interact with each other. One can not in general treat the electrons as independent particles. The interaction between the electrons will affect their motion and therefore the possibilities for extracting time-resolved information. The present project has addressed this issue by developing theory and numerical tools to describe the time-dependent laser-induced polarisation effect of the electron cloud. This effect creates an effective many-electron field on the active electron and results in more accurate modelling of the dynamics. This is progress beyond the state of the art.
In connection time-resolved dynamics and possibilities, it is a challenge to deal with the fact that the electrons interact with each other. One can not in general treat the electrons as independent particles. The interaction between the electrons will affect their motion and therefore the possibilities for extracting time-resolved information. The present project has addressed this issue by developing theory and numerical tools to describe the time-dependent laser-induced polarisation effect of the electron cloud. This effect creates an effective many-electron field on the active electron and results in more accurate modelling of the dynamics. This is progress beyond the state of the art.