1. RIKEN Center for Emergent Matter Science Wako‐shi Saitama 351‐0198 Japan
2. Physics & Informatics Laboratories (PHI Lab) NTT Research, Inc. Sunnyvale CA 94085 USA
3. ARC Centre of Excellence for Transformative Meta‐Optical Systems Department of Electronic Materials Engineering Research School of Physics The Australian National University Canberra ACT 2601 Australia
4. ARC Centre of Excellence in Future Low‐Energy Electronics Technologies and Department of Quantum Science and Technology Research School of Physics The Australian National University Canberra ACT 2601 Australia
5. Institute of Physics University of Oldenburg D‐26129 Oldenburg Germany
6. Technische Physik Physikalisches Institut and Wilhelm Conrad Roentgen‐Research Center for Complex Material System Universität Würzburg Am Hubland D‐97074 Würzburg Germany