1. Department of Materials, ETH Zurich, 8093 Zürich, Switzerland.
2. Department of Physics, ETH Zurich, 8093 Zürich, Switzerland.
3. Department of Advanced Materials Science, The University of Tokyo, Chiba 277-8561, Japan.
4. RIKEN Center for Emergent Matter Science (CEMS), Saitama 351-0198, Japan.
5. Department of Applied Physics and Tokyo College, The University of Tokyo, Tokyo 113-8656, Japan.
6. Institut des Molécules et Matériaux du Mans, UMR 6283 CNRS, Le Mans Université, 72085 Le Mans, France.