1. Electrical and Computer Engineering, New York University, Brooklyn, New York 11201, USA
2. Department of Physics, New York University, New York, New York 10003, USA
3. Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA
4. International Center for Materials Nanoarchitectonics, National Institute of Materials Science, 1-1 Namiki Tsukuba, Ibaraki 305-0044, Japan
5. Research Center for Functional Materials, National Institute of Materials Science, 1-1 Namiki Tsukuba, Ibaraki 305-0044, Japan
6. Center for Quantum Phenomena, Department of Physics, New York University, New York, New York 10003, USA