1. Helmholtz‐Zentrum Dresden‐RossendorfInstitute of Ion Beam Physics and Materials Research Bautzner Landstr. 400 Dresden 01328 Germany
2. Shenzhen Key Laboratory of Laser Engineering College of Physics and Optoelectronic EngineeringShenzhen University Shenzhen 518060 China
3. Technische Universität Dresden Dresden D‐01062 Germany
4. Center for Quantum Frontiers of Research & Technology (QFort)National Cheng Kung University Tainan 701 Taiwan
5. Institute for PhysicsMartin‐Luther‐University Halle‐Wittenberg Halle 06120 Germany
6. Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Optical Information Materials and TechnologySouth China Academy of Advanced OptoelectronicsSouth China Normal University Guangzhou 510006 China
7. Institute of PhysicsChemnitz University of Technology Chemnitz D‐09107 Germany
8. Department of Materials Science and EngineeringNational Chiao Tung University Hsinchu 30010 Taiwan