With the ground breaking work of the Fulde, Ferell, Larkin, and Ovchinnikov (FFLO), it was realized that superconducting order can also break translational invariance; leading to a phase in which the Cooper pairs develop a coherent periodic spatially oscillating structure. Such pair density wave (PDW) superconductivity has become relevant in a diverse range of systems, including cuprates, organic superconductors, heavy fermion superconductors, cold atoms, and high density quark matter. Here we show that, in addition to charge density wave (CDW) order, there are PDW ground states that induce spin density wave (SDW) order when there is no applied magnetic field. Furthermore, we show that PDW phases support topological defects that combine dislocations in the induced CDW/SDW order with a fractional vortex in the usual superconducting order. These defects provide a mechanism for fluctuation driven non-superconducting CDW/SDW phases and conventional vortices with CDW/SDW order in the core.
Visualization of vortex sheets and half quantum vortices in the chiral odd-parity superconductor UPt$_{3}$
Université Grenoble Alpes（格勒诺布尔阿尔卑斯大学）；CNRS（法国国家科学研究中心）；Institut Néel（奈尔研究所）；Aix Marseille Univ（艾克斯-马赛大学）；Université de Toulon（土伦大学）；IM2NP（物质与纳米结构物理化学研究所）；CEA（法国原子能和替代能源委员会）；IRIG（研究和技术集成部）；PHELIQS（低温、激光和量子科学实验室）；The University of Edinburgh（爱丁堡大学）；Centre for Science at Extreme Conditions（极端条件科学中心）；Tohoku University（东北大学）；Institute for Materials Research（材料研究所）
Proposal to stabilize and detect half-quantum vortices in strontium ruthenate thin films: Non-Abelian braiding statistics of vortex matter in a ${p_x}+i{p_y}$ superconductor
Observation of vortices and hidden pseudogap from scanning tunneling spectroscopic studies of electron-doped cuprate superconductor $Sr_{0.9}La_{0.1}CuO_2$
Dislocation Majorana Bound States in Iron-based Superconductors
我们发现，晶格位错的拓扑铁基超导体，如FeTe $_{1-x}$ Se $_x$将内在陷阱非阿贝尔马约拉纳准粒子，在没有任何外部磁场。我们的理论是由最近的实验观察的正常状态的拓扑结构和表面磁性共存的超导性FeTe $_{1-x}$ Se $_x$，其组合自然地唤起一个新兴的二阶拓扑超导性在一个二维子系统跨越的螺旋或刃位错。这证明了一个新的嵌入式高阶拓扑相在D类，其中马约拉纳零模式出现在一个低维嵌入式子系统的“角落”，而不是那些完整的晶体。嵌套畴壁理论的发展，以了解这些缺陷马约拉纳零模式的起源。当表面磁性是不存在的，我们进一步发现，$s_{\pm}$配对对称性本身是能够诱导一个不同类型的DIII类嵌入高阶拓扑结构与缺陷绑定马约拉纳Kramers对。我们还提供了详细的讨论，我们的建议，包括FeTe $_{1-x}$ Se $_x$，LiFeAs，$β$ -PdBi $_2$，和异质结构的铋等，我们的工作建立晶格缺陷作为一个新的场所，实现高温拓扑量子信息处理。
