1. Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
2. Department of Physics, Indian Institute of Science Education and Research Pune, Pune, Maharashtra 411008, India
3. International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
4. Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
5. Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States