TY - JOUR
T1 - Interlayer-state-driven superconductivity in CaC6 studied by angle-resolved photoemission spectroscopy
AU - Kyung, Wonshik
AU - Kim, Yeongkwan
AU - Han, Garam
AU - Leem, Choonshik
AU - Kim, Chul
AU - Koh, Yoonyoung
AU - Kim, Beomyoung
AU - Kim, Youngwook
AU - Kim, Jun Sung
AU - Kim, Keun Su
AU - Rotenberg, Eli
AU - Denlinger, Jonathan D.
AU - Kim, Changyoung
N1 - Publisher Copyright:
© 2015 American Physical Society.
PY - 2015/12/30
Y1 - 2015/12/30
N2 - We performed angle-resolved photoemission experiments on CaC6 and measured kz-dependent electronic structures to investigate the interlayer states. The results reveal a spherical interlayer Fermi surface centered at the Γ point. We also find that the graphene-driven band possesses a weak kz dispersion. The overall electronic structure shows a peculiar single-graphene-layer periodicity in the kz direction although the CaC6 unit cell is supposed to contain three graphene layers. This suggests that the c-axis ordering of Ca has little effect on the electronic structure of CaC6. In addition to CaC6, we also studied the a low-temperature superconductor BaC6. For BaC6, the graphene-band Dirac-point energy is smaller than that of CaC6. Based on data from CaC6 and BaC6, we rule out the Cxy phonon mode as the origin of the superconductivity in CaC6, which strongly suggests interlayer-state-driven superconductivity.
AB - We performed angle-resolved photoemission experiments on CaC6 and measured kz-dependent electronic structures to investigate the interlayer states. The results reveal a spherical interlayer Fermi surface centered at the Γ point. We also find that the graphene-driven band possesses a weak kz dispersion. The overall electronic structure shows a peculiar single-graphene-layer periodicity in the kz direction although the CaC6 unit cell is supposed to contain three graphene layers. This suggests that the c-axis ordering of Ca has little effect on the electronic structure of CaC6. In addition to CaC6, we also studied the a low-temperature superconductor BaC6. For BaC6, the graphene-band Dirac-point energy is smaller than that of CaC6. Based on data from CaC6 and BaC6, we rule out the Cxy phonon mode as the origin of the superconductivity in CaC6, which strongly suggests interlayer-state-driven superconductivity.
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U2 - 10.1103/PhysRevB.92.224516
DO - 10.1103/PhysRevB.92.224516
M3 - Article
AN - SCOPUS:84953383214
VL - 92
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 0163-1829
IS - 22
M1 - 224516
ER -