5th Institute of Physics

Final Theses Topics

Join our team for your Bachelor/Master thesis project!

We are always looking for motivated students to join us for their Bachelor / Master thesis project.

On this page you can find a list of topics currently offered for thesis projects at the 5th Institute of Physics. Information on the research project and team in which each topic is embedded as well as contact persons are provided below.

If you are interested in joining our team for your thesis work please do not hesitate to contact us.

Phatthamon Kongkhambut and Viraatt Anasuri share their experience as students in the Master's program PHYSICS and take us to their labs at the 5th Institute of Physics.

Duration: 2:17 | © University of Stuttgart | Source: YouTube

Bachelor Thesis Topics

This project is part of the trace gas sensing experiment where we aim to investigate a new kind of gas sensing scheme based on Rydberg excitations in nitric oxide. Within the scope of this thesis you will build and characterize a setup to dilute 10 ppm of nitric oxide in nitrogen down to the ppb level. The setup will consist of four mass flow controllers, two vacuum pumps the experiment’s cell and a pump control system to adjust the gas flow through the whole system. The goal is to be able to readout and control the system via a control PC.

Contact: Patrick Kaspar, Harald Kübler

Project: Trace Gas Sensing

As part of the trace gas sensing project this work will give useful information for the investigation of our sensing scheme using the new setup for Rydberg excitations in nitric oxide. The thesis is focused on measurements investigating collisional physics of rubidium Rydberg atoms and Trifluormethan. You will measure on an existing setup to acquire datasets for Rydberg states of rubidium with different principle quantum numbers. You will have to chance to evaluate the data you took by yourself and compare it to the data of other background gases taken within the scope of former Bachelor and Master theses.
In addition to acquiring data you will also learn how to prepare and maintain the laser system and frequency reference used to measure.

Contact: Patrick Kaspar, Harald Kübler

Project: Trace Gas Sensing

Within the scope of setting up of our new trace-gas sensing experiment for the detection of nitric oxide we need several lasers and transfer cavities to be set up and characterized. This project comprises several bachelor theses. Which topic can be assigned depends on our working schedule and progress in the lab.  Possible topics are: 1) Setup and stabilization of an 895 nm laser to an ultra-low expansion cavity using the Pound-Drever-Hall technique. 2) Setup of a new diode laser system and transfer cavity stabilized to the ULE cavity. 3) Setup and characterization of a transfer cavity for the fundamental laser of a frequency quadrupled UV-Laser system.

Contact: Patrick Kaspar, Harald Kübler

Project: Trace Gas Sensing

In our experiment, we plan to implement optical trapping of single ionic impurities that we create by photo-ionization of parent Rydberg impurities. For this to realize it is of importance to characterize the beam profile of a micro-meter sized optical tweezer. You will develop a fully automized Piezo-based scanning system to measure the point-spread-function of a micro-tweezer generated from a high-NA aspheric lens. The goal is to identify optimal laser beam parameters to balance diffraction limited performance and undesired geometric aberrations in view of realizing minimal spot sizes.

Contact: Florian Meinert

Project: Giant Rydberg Atoms in Ultracold Quantum Gases

The goal of this project will be to calculate the transition frequencies of our molecules by diagonalizing the molecular Hamiltonians. In a second step these calculations will be compared against actual measurements taken by the prospective student using our experimental setup. This spectroscopy has direct applications in precision measurements, where physics that usually require large-scale particle accelerators can be studied on a single optical table.

Contact: Tim Langen

Project: Cold Molecules

This project is a collaboration with the IHFG. We plan to develop a blue laser source in a compact package based on the VECSEL-technology developed at the IHFG. This light source will be integrated in our trace gas sensor project.

The new laser source will be compared to an existing commercial laser source at the PI5.

Contact: Robert Löw, Harald Kübler

Project: Quantum Optics with Hot Atoms

In this project theoretical and numerical investigations on pulsed four-wave mixing in rubidium µ-cell will be done. Temporal and spacial properties of the inverted excitation scheme including a Rydberg state are in focus. This topic is in context of the room-temperature single-photon emitter project.

Contact: Fabian Ripka, Harald Kübler

Project: Quantum Optics with Hot Atoms

When laser cooling diatomic molecules dark states can arise, which do not couple to the cooling lasers anymore. Hence, the cooling stops. A way to mitigate this is to rapidly switch the polarization of the laser light. Such switching can be accomplished using a so-called Pockels cell. The topic of this thesis will be to set up such a Pockels cell, characterize and test it in the lab and apply it to remix dark states in our experiments, e.g. by slowing down a molecular beam. The latter has never been achieved with our molecules before, and would thus be a significant step forward in molecular laser cooling.

Contact: Tim Langen

Project: Cold Molecules

Master Thesis Topics

This project is part of the trace gas sensing experiment with the goal to investigate a new kind of gas sensor for nitric oxide based on Rydberg excitations. This work aims to investigate the spectrum of the  X21/2,v = 0 → A2Σ+,v = 0 transition in the nitric oxide molecules. The transition lies in the deep UV with spectral lines between 224 nm and 227 nm. You will use our state of the art UV laser system to spectroscopically analyze the rotational structure and hyperfine structure of the aforementioned transition. The spectroscopy will be performed at room temperature in a gas cell filled with nitric oxide at a pressure in the mbar regime.

Contact: Patrick Kaspar, Harald Kübler

Project: Trace Gas Sensing

If you are interested in a cutting-edge interdisciplinary research on the interface of atomic physics, quantum optics, and Nano-photonics this is a proper project for you. Within the scope of this Master’s thesis, you will develop good theoretical understanding and experimental skills by working on an efficient integrated optical cavity embedded in an atomic vapor cell.

For further details please refer to this pdf file.

Contact: Hadiseh Alaeian, Tilman Pfau

Project: Quantum Optics with Hot Atoms

A Rydberg atom provide a single electron in a well defined quantum state that can cover thousands of atoms in a Bose-Einstein Condensate. We are interested to watch this single quantum imersed in a sea of atoms. On the one hand it can bind atoms into molecular states on the other habe it can backact on the collective excitations of a quantum gas. The interaction between the electron and the quantum gas is mediated by low energy scattering. The interaction depends on the electron spin and we have recently studies how this spin dependence can be used to excite very exotic "trilobite" molecules (see figure above) [2]. In this thesis we want to understand the transition from molecular physics to many-body physics [3] including the spin degree of freedom. In addition we want to study the depencence on the orbital angular momentum [4]. The experimenatl tool is high resolution spectroscopy on a BEC sample including single ion detection.

[1] Kathrin S. Kleinbach, Florian Meinert, Felix Engel, Woo Jin Kwon, Robert Löw, Tilman Pfau, Georg Raithel
"Photo-association of trilobite Rydberg molecules via resonant spin-orbit coupling"
Phys. Rev. Lett. 118, 223001 (2017)

[2] A. Gaj, A. T. Krupp, J. B. Balewski, R. Löw, S. Hofferberth, and T. Pfau
"From molecular spectra to a density shift in dense Rydberg gases"
Nature Comm. 5, 4546 (2014)

[3] A.T. Krupp, A. Gaj, J.B. Balewski, P. Ilzhöfer, S. Hofferberth, R. Löw, T. Pfau, M. Kurz, and P. Schmelcher,
"Alignment of D-state Rydberg molecules"
Phys. Rev. Lett. 112, 143008 (2014)

 

Contact: Florian Meinert

Project: Giant Rydberg Atoms in Ultracold Quantum Gases

 

The goal of this project will be the characterization and optimization of a cold beam of dipolar molecules using laser ablation in a cryogenic cell. In the cell, collisions with a cold Helium buffer gas thermalize the molecules to ∼4 K. The molecular beam is formed using an exit aperture in the cell, and provides very good starting conditions for subsequent laser cooling. During the thesis extensive computer simulations will be used to model and optimize this molecular beam and the dynamics inside the buffer gas cell. This will have direct applications in precision measurements, where physics that usually require large-scale particle accelerators can be studied on a single optical table.

Contact: T. Langen

Project: Cold Molecules

The current state-of-the-art theoretical model to describe strongly dipolar Bose-Eintein condensates of Dysprosium is the so-called extended Gross-Pitaevskii equation. This equation is based on the mean-field Gross-Pitaevskii equation including the long-range anisotropic dipole-dipole interaction, to which an effective term is added to take into account the effect of beyond-mean-field corrections. These correction arise from quantum fluctuations in the fluid and act as an effective extra non-linearity. The goal of this project is to perform simulations of this equation to compare to experiments in order to test the thepry at the current level and make useful predictions for our experiments on Dysprosium. These numerical simultions are developped in our group, and they allow to implement the exact experimental conditions.

Contact:Tilman Pfau

Project: Dipolar Quantum Gases

The usual laser cooling in atoms relies on the spontaneous force, which arises from many individual photon absorption and emission cycles. Molecules can typically only scatter a much smaller number of photons. Moreover, they feature many internal states. Taken together, this significantly reduces the magnitude and versatility of the spontaneous force for molecules. An promising alternative are stimulated forces, where instead of spontaneously decaying back into the ground state, the molecules return to the ground state by stimulated emission. The goal of this Master's thesis will be to calculate the forces in these processes, which can be orders of magnitude higher than spontaneous forces. Once understood, we will apply them to the molecules in our experiment for the first time.

Contact: T. Langen

Project: Cold Molecules

This project is a collaboration with the IHFG. We plan to develop a blue laser source in a compact package based on the VECSEL-technology developed at the IHFG. This light source will be integrated in our trace gas sensor project.

The new laser source will be compared to an existing commercial laser source at the PI5.

Contact: Robert Löw, Harald Kübler

Project: Quantum Optics with Hot Atoms

In this thesis a commercial laser system at 420 nm will be installed in combination with a full reference set-up for application in a new excitation scheme of Rydberg four-wave mixing. This topic is in context of the room-temperature single-photon emitter project.

Contact: Fabian Ripka, Harald Kübler

Project: Quantum Optics with Hot Atoms

In collaboration with ITO a high-numeric aperture solid-immersion lenses will be placed on a glass cell. Different lens geometries will be explored and characterized. This topic is in context of the room-temperature single-photon emitter project.

Contact: Fabian Ripka, Harald Kübler

Project: Quantum Optics with Hot Atoms

Within this thesis a laser system at near-UV wavelength will be set up. With this the effect of light-induced atomic desorption will be characterized in terms of optical depth and atomic dynamics. This topic is in context of the room-temperature single-photon emitter project.

Contact: Fabian Ripka, Harald Kübler

Project: Quantum Optics with Hot Atoms

 

This project focuses on a detection scheme for Rydberg atoms in thermal vapor based on pulsed field ionization. In collaboration with the electric engineering department a detection circuit based on a transimpedance amplifier will be developed and tested.

Contact: Patrick Kaspar, Harald Kübler

Project: Trace Gas Sensing

Teacher Candidate (Lehramt) Thesis Topics

The group "Physics Didactics Research" is constantly offering various topics for your final thesis projects. To find out more on current offerings please contact:

Ronny Nawrodt or

Holger Cartarius

Contact

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