1. Laboratoire Kastler Brossel, Sorbonne Universite, CNRS, ENS-PSL Research University, College de France, College de France, 4 place Jussieu, 75252 Paris, Cedex 05, France
2. Centre for Disruptive Photonic Technologies, The Photonics Institute, 21 Nanyang Link, Nanyang Technological University, Singapore 637371, Singapore
3. Interdisciplinary Graduate School, Energy Research Institute @NTU (ERI@N), Nanyang Technological University, 50 Nanyang Drive, Singapore 637553, Singapore
4. Division of Physics and Applied Physics, 21 Nanyang Link, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore