1. Airbus Group Innovations, D-81663 Munich, Germany
2. Department
of Applied Sciences and Mechatronics, Munich University of Applied Sciences, D-80335 Munich, Germany
3. Institute
of Experimental Physics I, Justus-Liebig-University Giessen, D-35392 Giessen, Germany
4. Institute
of Solid State Physics, University of Bremen, D-28359 Bremen, Germany