1. Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
2. KLA-Tencor (Singapore) Pte. Ltd., 4 Serangoon North Avenue 5, Singapore 554532, Singapore
3. MajuLab, International Joint Research Unit UMI 3654, CNRS, Universite Côte d’Azur, Sorbonne Universite, National University of Singapore, and Nanyang Technological University, Singapore 637371, Singapore