Interlayer-state-driven superconductivity in CaC 6 studied by angle-resolved photoemission spectroscopy

Wonshik Kyung,1 Yeongkwan Kim,1,2 Garam Han,1 Choonshik Leem,1 Chul Kim,1 Yoonyoung Koh,1 Beomyoung Kim,1 Youngwook Kim,3 Jun Sung Kim,3 Keun Su Kim,2,3,4 Eli Rotenberg,2 Jonathan D. Denlinger,2 and Changyoung Kim1,* 1Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Korea 2Advanced Light Source, Lawrence Berkeley National Laboratory, California 94720, USA 3Department of Physics, Pohang University of Science and Technology, Pohang 790-784, Korea 4Center for Artificial Low-Dimensional Electronic Systems, Institute for Basic Science, Pohang 790-784, Korea (Received 16 September 2014; revised manuscript received 21 October 2015; published 30 December 2015)