1. Department of Materials Science and EngineeringNational University of Singapore Singapore 117575 Singapore
2. Department of Physics and Astronomy and NebraskaCenter for Materials and NanoscienceUniversity of Nebraska Lincoln NE 68588 USA
3. NUSNNI‐NanocoreNational University of Singapore Singapore 117411 Singapore
4. Spintronics InstituteUniversity of Jinan Jinan 250022 China
5. Condensed Matter Science and Technology Institute and Department of PhysicsHarbin Institute of Technology Harbin 150001 China
6. School of Physical and Mathematical Sciences and School of Electrical and Electronic EngineeringNanyang Technological University Singapore 639798 Singapore
7. Singapore Synchrotron Light Source National University of Singapore 5 Research Link Singapore 117603 Singapore