Anisotropic Electron-Phonon Coupling and Dynamical Nesting on the Graphene Sheets in Superconducting CaC6 using Angle-Resolved Photoemission Spectroscopy
Anisotropic Electron-Phonon Coupling and Dynamical Nesting on the Graphene Sheets in Superconducting CaC6 using Angle-Resolved Photoemission Spectroscopy
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DOI：
10.1103/physrevlett.102.107007
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发表时间：
2009-03-13
影响因子：
8.6
通讯作者：
Ellerby, M.
中科院分区：
文献类型：
--
作者：
Valla, T.;Camacho, J.;Ellerby, M.
我们对CaC₆的电子结构进行了首次角分辨光电子能谱研究，CaC₆是一种超导石墨插层化合物，其临界温度\(T_{c}=11.6\)K。我们发现，与理论模型相反，在源自石墨烯的费米面上，与高频源自石墨烯的声子的电子 - 声子耦合出奇地强且具有各向异性。发现费米面的形状有利于通过高频声子的交换实现动态的谷间嵌套。我们的研究结果表明，石墨烯片在石墨插层化合物的超导性中起着至关重要的作用。
We present the first angle-resolved photoemission studies of electronic structure in CaC6, a superconducting graphite intercalation compound with T-c=11.6 K. We find that, contrary to theoretical models, the electron-phonon coupling on the graphene-derived Fermi sheets with high-frequency graphene-derived phonons is surprisingly strong and anisotropic. The shape of the Fermi surface is found to favor a dynamical intervalley nesting via exchange of high-frequency phonons. Our results suggest that graphene sheets play a crucial role in superconductivity in graphite intercalation compounds.