We are looking for talented and motivated students doing a Bachelor, project or Master Thesis in our group. Please find a below a list of current topics, by whom these are supervised (see AG Held), and what the requirements are.
Computational projects
We are developing the w2dynamics quantum Monte-Carlo code, have pioneered density functional theory (DFT) plus dynamical mean-field theory (DMFT), and invented new approaches such as the dynamical vertex approximation (DGA) based on many–body vertices. For the corresponding codes, see here. To test and implement new ideas, further improve, benchmark or parallelize the existing codes help is always welcome. For computational projects EDV for physicists or otherwise good coding skills are required.
- non-Abelian symmetry in exact diagonalization (MA,GT) supervision: Markus
- perfomance analysis of w2dynamics or exact diagonalization code (PA) supervision: Anna/Markus and Martin/Markus, respectively
- machine learning for analytic continuation (PA/MA,ML) supervision: Markus/Karsten
- intermediate representation (machine learning inspired) for solving the parquet equation of the Anderson impurity model (PA,ML) supervision: Samuel/Markus
- improving the exact diagonalization code for DMFT (PA) supervision: Martin
Physics projects
As theoretical solid state physicists, we have to do a lot of detective work, for finding pout what is going on in a solid, understanding and predicting new physical phenomena. The projects below aim at this, using existing code or only requiring minor modifications. Physics is at the focus.
- Hall coefficient in nickelate superconductors (PA) supervision: Paul/Simone
- exploring new thermoelectrics with density functional theory (PA,SSP) supervision: Simone
- electron-phonon mediated superconductivity boosted by hydrogen (PA/MA,SSP) supervision: Simone
- quantum Fisher information in the pseudogap regime and for quantum critical points (PA) supervision: Karsten/Anna/Friedrich
- topology of the pseudogap phase (PA) supervision: Karsten
- weak localization on the triangular lattice (PA/MA, QFT recommended) supervision: Anna
- optical conductivity calculated with TUPS (PA/MA, QFT recommended) supervision: Anna
- pi-tons (a new polariton) on a six site ring calculated with exact diagonalization (PA) supervision: Anna/Karsten
- reduced density matrix for 2-site Anderson impurtiy model calculated with exact diagonalization (PA) supervision: Markus/Karsten
Theoretical projects
We do theoretical physics. Sometimes a computer code is at the focus of a project, sometimes it is a physical phenomena, and sometimes it is the theory as such. E.g. when developing new approaches or studying the mathematics behind the objects employed (such as the vertex). The latter projects are listed here.
- 2-site reduced density matrix for lattice models (PA, QFT of advantage) supervision: Anna/Karsten
- high frequency asymptotics of the Hedin vertex (PA, QFT of advantage) supervision: Friedrich
- Loschmidt amplitude for non-equilibrium optical conductivity (PA) supervision: Anna
Acronyms:
Type of work/thesis
PA: project work (Projektarbeit). Can also be Bachelor Thesis depending on the requirements.
MA: Master Thesis
Requirements
QFT: Quantum field theory (e.g. elective lecture quantum field theory for many-body systems)
ML: elective lecture machine learning in physics
SSP: solid state physics (lattice, Brillouin zone...)
GT: Group theory
All our research is fundamentally based on quantum mechanics, hence require the quantum theory 1 lecture.