Superconductivity on the brink of spin-charge order in a doped honeycomb bilayer.
Superconductivity on the brink of spin-charge order in a doped honeycomb bilayer.
复制标题
掺杂蜂窝状双层中处于自旋电荷序边缘的超导性。
DOI：
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发表时间：
2013
影响因子：
8.6
通讯作者：
V. Cvetkovic
中科院分区：
文献类型：
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作者：
O. Vafek;J. M. Murray;V. Cvetkovic
利用受控的弱耦合重整化群方法，我们建立了电子在Bernal堆叠双层蜂窝晶格上自旋或电荷有序激子态附近的非常规超导机制。由于每个位置有一个电子，该系统在物理上实现在双层石墨烯中，不稳定的自发对称性破缺。排斥相互作用有利于激子秩序，如电荷向列和/或层反铁磁体。我们发现，在系统中加入载流子后，激子秩序被抑制，在被费米液体取代之前，非常规的超导性出现在其位置。我们着重于在一个具有传导带和价带抛物线接触的理想模型中使用重整化群形式化来牢固地建立这一现象。
Using a controlled weak-coupling renormalization group approach, we establish the mechanism of unconventional superconductivity in the vicinity of spin or charge ordered excitonic states for the case of electrons on the Bernal stacked bilayer honeycomb lattice. With one electron per site, this system, physically realized in bilayer graphene, is unstable towards a spontaneous symmetry breaking. Repulsive interactions favor excitonic order, such as a charge nematic and/or a layer antiferromagnet. We find that upon adding charge carriers to the system, the excitonic order is suppressed, and unconventional superconductivity appears in its place, before it is replaced by a Fermi liquid. We focus on firmly establishing this phenomenon using the renormalization group formalism within an idealized model with parabolic touching of conduction and valence bands.