If you are looking for a Bachelor, Master, or PhD position, please have a look at the different research topics we are offering at the moment.
Bachelor- and Master-Positions
In this theory/simulation project you will employ Machine Learning algorithms (Supervised, Unsupervised) on data obtained from Quantum sensing experiments. You will develop a training model to recognize field-patterns and learn features on ODMR and spin life-time measurement data obtained from various experiments. Further these training models will be used to make new predictions on the analyzed data. You will use the standard classical ML algorithms and also develop parametrized quantum circuits and optimize them to suit a particular use-case (for example performing a classification on a dataset).
Modern quantum information processing relies on fast and precise control of quantum bits. Algorithms require the fidelity of each operation to exceed 99% and indeed scalable quantum computers require even larger numbers. Achieving such high precision requires sophisticated quantum control. In the thesis we will apply quantum optimal control algorithms to single quantum bits. This numerical method achieves high gate fidelities by optimizing quantum control under a predefined stet of boundary conditions. We will install these algorithms on new ultrafast hardware with the goal to attain increased precision in quantum error correction. The achieved gain in fidelity will be experimentally tested and the developed software will be integrated into an existing software package.
Contact: Prof. Dr. Jörg Wrachtrup
The aim would be to demonstrate the minimal model of a quantum heat machine (for both quantum heat engines and refrigerators) made of a single driven two-level NV qubit simultaneously coupled to spectrally distinct hot and cold baths. The dependence of the quantum refrigerator cooling rate and efficiency on the bath spectra and modulation rate of the coupling between the qubit and the baths will be analysed both theoretically and experimentally. For experiments two spin-baths made of 13C nuclear spins will be used to demonstrate the working principle of the Quantum Refrigerator.
Contact: Dr. Durga Dasari
The aim here would be to use quantum control theory to design methods to sense the dynamics of strongly interacting many-spin systems, which include 2D spin models, Skyrmions, spin-Maser etc. Using both analytical and computational methods, you will produce a library of pulse sequences with targeted functionality in sensing interacting spin systems. Further, (as time permits) you will use these results to design a sequence for detecting thermalization in closed systems using a quantum sensor.
Contact: Dr. Durga Dasari
Rare earth ions in optical crystals are potentially excellent candidates for quantum computing applications as qubits and quantum memory. So far, most of quantum features of rare earth ions were studied and exploited in ensembles containing many (billions) of ions. However, for scalable quantum computing single ion qubits are preferred. As of now, only two rare earth species, namely, cerium and praseodymium, were detected optically at a single ion level. Extending the list of detectable ions would strengthen the whole field of rare earth quantum computing.
The proposed master project is aiming at optical detection of a single divalent europium ion in various hosts. While some of the host materials, such as CaF2, are readily available as single crystals, the most interesting having no intrinsic nuclear spins ones can be obtained primarily as micro- and nano-powders. If the detection of Eu2+ ion is achieved at early stage of the project, the focus of the work will be shifted on studying electron and nuclear spin properties of the potential europium qubit.
The project will involve many aspects of materials science and optical characterization in confocal microscopes. It also implies close collaboration with material science groups at Max-Planck Institute as well as with implantation groups in Bochum, Augsburg, and Leipzig.