Bogoliubov Fermi surfaces stabilized by spin-orbit coupling
Bogoliubov Fermi surfaces stabilized by spin-orbit coupling
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DOI：
10.1103/physrevb.100.224505
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发表时间：
2019-09
影响因子：
3.7
通讯作者：
H. Menke;Carsten Timm;P. Brydon
中科院分区：
文献类型：
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作者：
H. Menke;Carsten Timm;P. Brydon
最近人们认识到，打破时间反演对称性的中心对称多带超导体一般表现为Bogoliubov准粒子的费米面。我们研究这些Bogoliubov费米面的热力学稳定性在一个范式模型。为此，我们构建了作为自旋轨道耦合和温度的函数的平均场相图。这证实了Bogoliubov费米面的配对状态可以稳定在中等的自旋轨道耦合强度的预测。该模型的多带性质也引起了一阶相变，这可以解释为带内和带间配对的竞争，并受到立方各向异性的强烈影响。对于具有Bogoliubov费米面的态，我们还讨论了剩余态密度和感生磁序的实验特征。我们的结果表明，Bogoliubov费米表面的实验相关的大小可以是热稳定的。
It was recently understood that centrosymmetric multiband superconductors that break time-reversal symmetry generically show Fermi surfaces of Bogoliubov quasiparticles. We investigate the thermodynamic stability of these Bogoliubov Fermi surfaces in a paradigmatic model. To that end, we construct the mean-field phase diagram as a function of spin-orbit coupling and temperature. It confirms the prediction that a pairing state with Bogoliubov Fermi surfaces can be stabilized at moderate spin-orbit coupling strengths. The multiband nature of the model also gives rise to a first-order phase transition, which can be explained by the competition of intra- and interband pairing and is strongly affected by cubic anisotropy. For the state with Bogoliubov Fermi surfaces, we also discuss experimental signatures in terms of the residual density of states and the induced magnetic order. Our results show that Bogoliubov Fermi surfaces of experimentally relevant size can be thermodynamically stable.