1 Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Bunkyo-ku, Tokyo, Japan. hirschberger@ap.t.u-tokyo.ac.jp.
2 RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama, Japan. hirschberger@ap.t.u-tokyo.ac.jp.
3 Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
4 RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama, Japan.