[1] Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z4, Canada
[2] Univ British Columbia, Stewart Blusson Quantum Matter Inst, Vancouver, BC V6T 1Z4, Canada
[3] RIKEN Ctr Emergent Matter Sci CEMS, 2-1 Hirosawa, Wako, Saitama 3510198, Japan
[4] Univ Tokyo, Dept Appl Phys, Bunkyo Ku, 7-3-1 Hongo, Tokyo 1138656, Japan