Author Affiliations

Sang Hoon Chae,¹ Dongjea Seo,² Qingrui Cao,³ Xiang Hua,³ En-Min Shih,⁴ Takashi Taniguchi,⁵ Kenji Watanabe,⁵ Junyoung Kwon,² Gwan-Hyoung Lee,² Cory R. Dean,⁴ David Schiminovich,⁶ Irving P. Herman,³ Heon-jin Choi,² Ioannis Kymissis,⁷ Young Duck Kim,⁸ and James Hone¹

¹Department of Mechanical Engineering, Columbia University, New York, New York 10027, USA

²Department of Materials Science and Engineering, Yonsei University, Seoul 03722, Republic of Korea

³Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, USA

⁴Department of Physics, Columbia University, New York, New York 10027, USA

⁵National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan

⁶Department of Astronomy, Columbia University, New York, New York 10027, USA

⁷Department of Electrical Engineering, Columbia University, New York, New York 10027, USA

⁸Department of Physics, Kyung Hee University, Seoul 02447, Republic of Korea