Open Positions
MSc and BA Projects
1. General Information
Our group offers a range of MSc and BA projects in theoretical quantum physics with topics ranging from quantum computational optimization to the emergence of collective phenomena in non-equilibrium many-body dynamics and to projects on quantum matter in cavities.
How MSc and BA projects work
At the start of their project students are given a project description. This will serve as an initial guide and students are expected to produce more detailed project plans during the initial phase of their project. These should be changed and updated by the student as the project evolves and new insights into the physics are gained.
The initial project description provides a list of important publications related to the topic of the project. This is usually accompanied by a set of tasks that should be completed prior to starting the actual research work and will enable students to quickly familiarize themselves with the research project.
The main part of the project is described as a set of specific tasks that can be carried out during the first half of the research project. These tasks are structured such that their successful completion will enable students to write a good quality MSc or BA thesis.
For the majority of students, we expect that these tasks will leave plenty of time to expand the research project further and to explore additional research questions. These additional questions will often arise from the initial tasks and the study of the literature. Suggestions for possible directions for extra tasks may also be contained in the initial project description. This second part of the project thus allows students to independently explore research questions and take the project into promising new directions.
The inclusion of research results arising from these additional topics will substantially strengthen any thesis. In addition, we might find that such research results can be published, either as standalone publications or as part of a larger effort.
Thus, there is a good chance – but no guarantee – that an MSc project and sometiemes even a BA project will allow students to become an author of a physics publication. The insights gained into the publishing process will be highly useful should students decide to carry on working in bacis research.
We expect most students to work closely with PhD students and/or PostDocs in the group and to benefit from their research experience. In addition, students will have regular meetings with Prof. Jaksch to discuss their progress and will be invited to participate in group meetings, journal clubs, etc. Please note that we are a highly international group and thus most communication within the group is in English.
If you’re interested, please contact us via jaksch-office.physik@uni-hamburg.de to arrange an initial meeting about currently available specific research projects. During this meeting, you will have the opportunity to meet group members and discuss their ongoing research to gain insights and explore potential research student positions.
2. Current MSc Projects
Magnetic properties of frustrated lattices
The emergence of magnetic order from strongly interacting many-body systems has been an active research area in condensed matter for at least the last 70 years. Recently, research has focused intensely on magnetism in frustrated geometries. These are very challenging and interesting systems from a fundamental perspective, and they also hold potential for numerous applications in spintronics or quantum technologies. This master project will build on a recent breakthrough we have achieved in the theoretical understanding of these systems [1].
Preliminary Work and objectives:
In our recent preprint [1], we have analytically derived the magnetic ground state properties of a class of frustrated lattices: so-called superstable graphs. We expect systems with these lattices to show first-order quantum phase transitions into a regime, the superstable regime, where even though the system has geometric frustration, its magnetic properties can be understood from non-frustrated geometries. This regime has the potential to host topological spin textures due to charge fluctuations and to explain superconducting condensation in photoexcited systems. Superstable graphs describe systems of interest e.g including spin-Peierls transitions, altermagnetism, and flat-band physics. In particular, based on the results in [2], we were able to estimate that more than two thousand materials could host superstable phases. These results, however, are limited to systems that are also expected to host flat-band physics.
The main objective of this master project is to identify a broader class of candidate materials that could host superstable regimes and the predicted phase transition through a systematic search in the Materials Project database [6]. The task of the student is to extract information from the database to identify candidate materials with lattice structures that could be explored in the superstable regime. In particular, the student will develop code to map the information in the database into a tight-binding model that describes the lattice structure and subsequently identify superstable graphs from these lattices.
In the following, we describe the first few steps of this MSc project in detail. Once these are complete, you will have sufficient material to write a good thesis. Ideally, a couple of months should be left to explore more advanced questions and broaden the scope of your work beyond these initial points.
1. Read [3] to learn how to build tight binding models based on a lattice geometry within the second quantization formalism. From this, you should build intuition for how lattice geometry influences the dispersions of the system. You will later automate the process of finding dispersion relations based on an input lattice structure.
2. Familiarize yourself with the concept of flat-band systems and its relevance in condensed matter physics by reading [4].
3. Read Ref. [2], this will be the main guide for your work. Keep notes on how the tight-binding models are extracted and the approximations made during the process. Pay attention to the crystal structure decomposition the authors use and the filtering to exclude trivial flat-bands. These notes will help you construct the introduction of your thesis.
4. Start familiarizing yourself with the information in the Materials Project and how to read its data: see the Materials Project commentary [5] and the Materials Project documentation [7].
5. Reproduce the results in [2]; this involves, in particular, creating code to find tight-binding models from the information in the Materials Project to obtain the corresponding lattice and the band structures for hundreds of thousands of materials.
6. Learn about the Hubbard model (see [8] up to chapter 7), pay attention to the main physical consequences of including electron-electron interactions in the picture.
7. Read [1], in particular the end matter in detail. There you will learn how to identify superstable graphs based on an input lattice structure.
8. Create an algorithm to detect superstable graphs from the unit cell of the lattices that you can generate with the code constructed in step 5.
9. Apply this algorithm to candidate lattice structures obtained from the information in the Materials Project to find materials that could host superstable phases.
Possible further directions:
Are there interesting materials where the superstable phase has been observed? This can be estimated from anisotropies in the lattice hoppings, this implies extending the algorithm to account for inhomogeneities in the hopping parameters within a unit cell.
In the case there is any interesting material with quasi-1D lattice structure not reported in [2] where our results might be relevant, a possible direction is to characterize the ground state phase diagram of such lattice with DMRG calculations and compare with experimental data.
Do the candidate materials identified in your research host interesting many-body phases like superconductivity or quantum spin liquids? If so, can a connection be made to the results of [1]?
References
[1] F. P. M. Mendez-Cordoba, J. Tindall, D. Jaksch, and F. Schlawin, On the magnetization of electronic ground states in frustrated superstable graphs, arXiv:2509.07079 (2025).
[2] P. M. Neves, J. P. Wakefield, S. Fang et al., Crystal net catalog of model flat band materials, npj Comput. Mater. 10, 39 (2024).
[3] W. P. Lima, F. R. V. Araújo, D. R. da Costa et al., Tight-binding model in first and second quantization for band structure calculations, Braz. J. Phys. 52, 42 (2022).
[4] D. Leykam, Flat bands, sharp physics, AAPPS Bull. 34, 2 (2024).
[5] A. Jain, S. P. Ong, G. Hautier et al., The Materials Project: A materials genome approach to accelerating materials innovation, APL Mater. 1, 011002 (2013).
[6] Materials Project, The Materials Project (materials database, 2025), https://next-gen.materialsproject.org (accessed September 29, 2025).
[7] Materials Project, Materials Project Documentation (2025), https://docs.materialsproject.org (accessed September 29, 2025).
[8] R. T. Scalettar, An introduction to the Hubbard Hamiltonian, in Quantum Materials: Experiments and Theory, eds. E. Pavarini et al., Modeling and Simulation 6 (Forschungszentrum Jülich, 2016).
PhD Positions
PhD positions will be announced on the University of Hamburg job opportunities page.
For further information, please contact us via jaksch-office.physik@uni-hamburg.de
Postdoc Positions
Postdoc positions will be announced on the University of Hamburg job opportunities page.
For further information, please contact us via jaksch-office.physik@uni-hamburg.de