Extended van Hove Singularity and Superconducting Instability in Doped Graphene
Extended van Hove Singularity and Superconducting Instability in Doped Graphene
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DOI：
10.1103/physrevlett.104.136803
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发表时间：
2010-04-02
影响因子：
8.6
通讯作者：
Rotenberg, Eli
中科院分区：
文献类型：
--
作者：
McChesney, J. L.;Bostwick, Aaron;Rotenberg, Eli
我们用角度分辨光电子能谱研究了掺杂对单层石墨烯的影响。我们发现，多体相互作用严重扭曲了费米面，导致了石墨烯M点的扩展范霍夫奇点(EVHS)。计算了具有这种EVHS的石墨烯的基态性质，分析了磁不稳定性和超导倾向之间的竞争。我们发现后者占主导地位，因为费米线上相互作用的强烈调制增强了后者，当费米能量足够接近EVHS时，导致配对不稳定性开始的能量标度高达1 meV。
We have investigated the effects of doping on a single layer of graphene using angle-resolved photoemission spectroscopy. We show that many-body interactions severely warp the Fermi surface, leading to an extended van Hove singularity (EVHS) at the graphene M point. The ground state properties of graphene with such an EVHS are calculated, analyzing the competition between a magnetic instability and the tendency towards superconductivity. We find that the latter plays the dominant role as it is enhanced by the strong modulation of the interaction along the Fermi line, leading to an energy scale for the onset of the pairing instability as large as 1 meV when the Fermi energy is sufficiently close to the EVHS.