1. Department of Electrical Engineering and Computer Science, FH Münster—University of Applied Sciences, Stegerwaldstr. 39, 48565 Steinfurt, Germany
2. Quantum Technologies GmbH, Alte Messe 6, 04103 Leipzig, Germany
3. Leibniz Institute of Surface Engineering (IOM), Permoserstr. 15, 04318 Leipzig, Germany
4. Department of Engineering Physics, FH Münster—University of Applied Sciences, Stegerwaldstr. 39, 48565 Steinfurt, Germany