1. School of Physics, Center of Excellence in Advanced Functional Materials, Institute of Science, Suranaree University of Technology, 3000 Nakhon Ratchasima, Thailand
2. Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622 Villeurbanne, France
3. Department of Physics, Nagoya University, 464-8602 Nagoya, Japan