1. Department of Physics, Indian Institute of Science, Bangalore 560012, India
2. Centre for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560012, India
3. Department of Electrical Communication Engineering, Indian Institute of Science, Bangalore 560012, India
4. Department of Physics, Indian Institute of Science Education and Research Mohali, Punjab 140306, India
5. Research Center for Electronic and Optical Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
6. Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
7. Centre for Nanoscience and Engineering, Indian Institute of Science, Bangalore 560012, India