This Bachelor's thesis is still in progress, expected to be completed by July 2025.
Johannes Porsch (Jo.Porsch@campus.lmu.de, joporsch04@gmail.com)
Multiphoton ionization of atoms in strong laser fields is a fundamental process in attosecond physics. In this work, I extend the strong-field approximation (SFA) by incorporating the influence of excited atomic states on ionization rates. Standard SFA formulations neglect these excited states, assuming that the laser field has no effect on the atom before ionization. However, in intense few-cycle laser pulses, the Stark shift and transient population of excited states can significantly modify ionization dynamics. I numerically solve the time-dependent Schrödinger equation (TDSE) using the tRecX code to extract time-dependent probability amplitudes for hydrogen’s ground and excited states. These amplitudes are then integrated into the SFA formalism to evaluate their impact on ionization rates.
- Anatomy of strong field ionization
- Theory of Nonlinear Photoconductive Sampling in Atomic Gases
- An environment for solving schrödinger-like problems
git clone https://github.com/joporsch04/Bachelor-thesis
The folder TIPTOE-Hydrogen was created during a research assistant position at MPQ during summer 2024 and not part of this thesis. It is a git submodule and can be cloned with:
git submodule update --init --recursive
cd TIPTOE-Hydrogen
git pull origin main
For the installation of tRecX, please visit this link. For simple testing I recommend using Docker. The dockerfile can be found in the folder tRecX:
link
cd tRecX
docker build -t trecx .
docker run -it trecx
If you choose to use a VM, pay attention to the Linux version. In some distributions libatlas-base-dev and libboost-all-dev are not compatible. In any case, the dockerfile (Ubuntu 22.04) works fine. The changes I made in tRecX are in the folder tRecX. The dockerfile already has the changes implemented.
The ionisation model is implemented in python.
For more information about the institute, please visit the official website: MPQ Homepage