1. Peter Grünberg Institut (PGI‐9) Forschungszentrum Jülich 52425 Jülich Germany
2. JARA‐Fundamentals of Future Information Technology Jülich‐Aachen Research Alliance Forschungszentrum Jülich and RWTH Aachen University 52425 Jülich Germany
3. Technical Center for Multifunctional Magneto‐Optical Spectroscopy (Shanghai) Engineering Research Center of Nanophotonics & Advanced Instrument (Ministry of Education) Department of Materials School of Physics and Electronics Science East China Normal University Shanghai 200241 China
4. Department of Physics and Astronomy and Department of Electrophysics University of Southern California Los Angeles CA 90089 USA
5. Ernst Ruska Center Forschungszentrum Jülich 52425 Jülich Germany
6. Institute of Complex Systems (ICS‐8) Forschungszentrum Jülich 52425 Jülich Germany