Instability of j=32 Bogoliubov Fermi surfaces
Instability of
j=32
Bogoliubov Fermi surfaces
复制标题
j=32 Bogoliubov 费米面的不稳定性
DOI：
10.1103/physrevb.102.020501
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发表时间：
2019
影响因子：
3.7
通讯作者：
E. Moon
中科院分区：
文献类型：
--
作者：
H. Oh;E. Moon
包括拓扑态和非费米液体在内的奇异量子相可以通过总角动量$j=3/2$的量子态来实现，如HgTe和焦绿石铱酸盐。最近，在一个具有Z$_2$拓扑不变量保护的中心对称$j=3/2$体系中，提出了一种具有零能量Bogoliubov （BG）准粒子态非零密度的奇异超导态Bogoliubov费米表面（BG- fs）。本文考虑了中心对称BG-FS的相互作用效应，并利用平均场和重整化群分析证明了其不稳定性。在与反演对称相关的波动通道中表现出Bardeen-Cooper-Schrieffer （BCS）型对数增强。因此，我们认为逆对称不稳定性是BG- fs在BG准粒子间一般吸引相互作用下的内在特征。与标准的BCS超导性形成鲜明对比的是，即使存在不稳定性，费米表面也可能普遍存在。我们提出了一种实验装置，一种具有应变梯度的二次谐波产生实验，以检测不稳定性。还讨论了在铁基超导体和包括FeSe在内的重费米子系统中的可能应用。
Exotic quantum phases including topological states and non-Fermi liquids may be realized by quantum states with total angular momentum $j=3/2$, as manifested in HgTe and pyrochlore iridates. Recently, an exotic superconducting state with non-zero density of states of zero energy Bogoliubov (BG) quasiparticles, Bogoliubov Fermi-surface (BG-FS), was also proposed in a centrosymmetric $j=3/2$ system, protected by a Z$_2$ topological invariant. Here, we consider interaction effects of a centrosymmetric BG-FS and demonstrate its instability by using mean-field and renormalization group analysis. The Bardeen-Cooper-Schrieffer (BCS) type logarithmical enhancement is shown in fluctuation channels associated with inversion symmetry. Thus, we claim that the inversion symmetry instability is an intrinsic characteristic of a BG-FS under generic attractive interactions between BG quasiparticles. In drastic contrast to the standard BCS superconductivity, a Fermi-surface may generically survive even with the instability. We propose the experimental setup, a second harmonic generation experiment with a strain gradient, to detect the instability. Possible applications to iron based superconductors and heavy fermion systems including FeSe are also discussed.
影响因子：
8.6
作者：
I. Boettcher;I. Herbut
通讯作者：
I. Boettcher;I. Herbut
影响因子：
3.7
作者：
Brydon, P. M. R.;Agterberg, D. F.;Timm, C.
通讯作者：
Timm, C.
影响因子：
8.6
作者：
Herbut, Igor F.;Janssen, Lukas
通讯作者：
Janssen, Lukas