1. Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
2. MajuLab, International Joint Research Unit UMI 3654, CNRS, Université Côte d’Azur, Sorbonne Université, National University of Singapore, Nanyang Technological University, Singapore 637371, Singapore
3. Laboratoire Pierre Aigrain, Département de physique de l’ENS, Ecole Normale Supérieure, PSL Research University, Université Paris Diderot, Sorbonne Paris Cité, Sorbonne Universités, UPMC Univ. Paris 06, CNRS, Paris 75005, France
4. CNR NANOTEC Institute of Nanotechnology, via Monteroni, Lecce 73100, Italy
5. State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, P.R. China
6. Beijing Academy of Quantum Information Sciences, Beijing 100193, P.R. China