Engineering Topological States in Germanium Quantum Wells

Future quantum computers will rely on robust quantum states that are protected from environmental noise. Majorana zero modes, emerging at the edges of topological superconductors, are leading candidates for building such noise-resistant quantum systems. Precise control over the coupling between quantum dots and superconductors is critical for their realization. This project will implement Kitaev chains - a paradigmatic model for topological superconductivity - using arrays of coupled quantum dots in germanium quantum wells.

The project will use electron beam lithography, thin film deposition, and ultra-low temperature measurements to produce and characterize devices where quantum dots are coupled through superconducting elements. The quantum properties of these hybrid systems will be probed through detailed transport measurements, with particular focus on signatures of emerging Majorana states. The stability and coherence properties of the engineered topological states will be systematically investigated toward establishing a scalable platform for topological quantum computation.

Through this project, the student will develop expertise in advanced nanofabrication techniques, ultra-low temperature measurements, quantum transport experiments, and sophisticated data analysis methods. They will gain hands-on experience with state-of-the-art equipment in the department's nanofabrication and measurement facilities.

The project combines expertise across quantum dot engineering and topological states of matter, leveraging recent breakthroughs in realizing Majorana-like states in semiconductor-superconductor hybrid systems. It will contribute to the UK-wide effort to develop new platforms for quantum technologies. The work will be carried out in the newly established quantum devices group led by Dr. Greg Mazur, in close collaboration with leading theorists and experimentalists working on related topics in quantum devices and topological matter.

Informal inquiries can be directed to greg.mazur@materials.ox.ac.uk