1. Leibniz Institute for Solid State and Materials Research Dresden, 01069 Dresden, Germany
2. Technical University Bergakademie Freiberg, 09599 Freiberg, Germany
3. Würzburg-Dresden Cluster of Excellence ct.qmat, Technical University Dresden, 01069 Dresden, Germany
4. Technical University Dresden, 01069 Dresden, Germany
5. Brandenburg University of Technology Cottbus-Senftenberg, 01968 Senftenberg, Germany