1. Advanced Research Institute for Correlated-Electron Systems (ARiCES), Department of Physics, National University of Singapore 1 , 2 Science Drive 3, Singapore 117551, Singapore
2. Singapore Synchrotron Light Source 2 , 5 Research Link, Singapore 117603, Singapore
3. Applied Materials 3 , 10 Science Park Road, Singapore 117684, Singapore
4. NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore 4 , Singapore 117456, Singapore