Department of Physics and Astronomy, Clemson University, Clemson, South Carolina 29634, USA.
Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26506, USA.
Phys Rev Lett. 2019 Aug 9;123(6):060402. doi: 10.1103/PhysRevLett.123.060402.
Higher-order topological superconductors hosting Majorana-Kramers pairs (MKPs) as corner modes have recently been proposed in a two-dimensional quantum spin Hall insulator proximity-coupled to unconventional cuprate or iron-based superconductors. Here, we show that such MKPs can be realized using a conventional s-wave superfluid with a soliton in cold atom systems governed by the Hubbard-Hofstadter model. The MKPs emerge in the presence of interaction at the "corners" defined by the intersections of line solitons and the one-dimensional edges of the system. Our scheme is based on the recently realized cold atom Hubbard-Hofstadter lattice and will pave the way for observing possible higher-order topological superfluidity with conventional s-wave superfluids or superconductors.
最近有人提出，在二维量子自旋霍尔绝缘体与非常规铜酸盐或铁基超导体近邻耦合的情况下，高阶拓扑超导体可以作为角模式承载马约拉纳-克拉默斯对 (MKP)。在这里，我们展示了在冷原子系统中由 Hubbard-Hofstadter 模型控制的、具有孤子的常规 s 波超流体中可以实现这种 MKP。在由线孤子和系统一维边缘相交处定义的“角”处存在相互作用时，会出现 MKP。我们的方案基于最近实现的冷原子 Hubbard-Hofstadter 晶格，将为观察具有常规 s 波超流或超导体的可能高阶拓扑超流性铺平道路。
