Hole spin qubits in electrically defined quantum dots within Germanium quantum wells in Silicon-Germanium heterostructures display a great platform for future quantum technologies. There have been exciting results like high quality two qubit gates, extensive material characterization and a fully operable 4 qubit processor in the few years, making it the most promising spin qubit platform besides electron spins in Silicon. One of reasons for its fast success are the lowered fabrication requirements, with the lower effective mass enabling larger functional gate structures as well as the possibility of all electrical driving of hole spins due to a large spin orbit interaction. Especially useful is also the ability to form energetically small Schottky barriers to the valence band with virtually any metal, removing the necessity of ion implantation and crystal reformation and replacing it by interdiffused contacts by metal evaporation directly onto the heterostructure and heating of the sample. Since dopants are believed to influence the heterostucture in a larger area around the contacts, conventional contacts are usually retracted several microns from the quantum dots. In Germanium distances between the actual dots and the interdiffused contacts is often just hundreds of nanometers on the surface. Since interface defects can be a dominant noise source in quantum dots, investigating the noise spectral density on differently far retracted Ohmic contacts experimentally is of large interest for the material platform and will be investigated in this project.
To be part of this project, you must have basic theoretical understanding of spin physics and quantum transport. You must be able to work in a small team and collaborate with students working on diverse projects with the same setup. Given that all of the measurements that we do are code-based, we require you to have experience with Python and object oriented programming.
What we offer
- Workplace, laptop for duration of the project.
- Student assistant contract via RWTH, or equivalent via FZ Jülich contract
- Young, international, dynamical workplace, located on Campus Melaten (Campus- Boulevard 79)
- Exposure to leading research activities in quantum technology