论文标题
具有非共线旋转顺序的自旋流性手性超导体中的主要涡流模式：状态的局部密度研究
Majorana vortex modes in spin-singlet chiral superconductors with noncollinear spin ordering: Local density of states study
论文作者
论文摘要
在本研究中，在手性旋转式超导性的共存阶段中描述了拓扑非平凡的边缘和涡旋结合状态，而在少量（多达四个）涡旋的情况下，在三角形晶格上进行了非连线性旋转顺序。我们考虑了托管主要模式和手性D-WAVE超导的初始阶段在支持非Majorana模式的手性D-WAVE超导性的初始阶段之间引起的拓扑相变，这在拓扑上也不普遍。在存在涡流的情况下，在两个开放和周期性边界条件的情况下，在临界点的激发光谱的变化均可获得。事实证明，在涡旋芯处定位的零能量主体模式是由非共聚的长距离磁有序引起的。即使附近的子段状态的激发能在内，包括边缘位置和涡旋 - 定位状态非常接近，但不同涡流结合状态之间的能量差也是一个数量级。这种差异决定了将它们与其他涡流结合状态分开的Majorana涡流模式的能量差距。已经发现，即使在非共线旋转顺序的存在下，也可以从纯手性d波状态的涡流状态的激发能量中估算出非磁性案例的激发能。通过研究涡流核附近的局部密度，讨论了通过扫描隧道显微镜实验检测到所述的Majorana涡流模式的可能性。事实证明，由于超导顺序参数上的手性对称性，非共线磁性诱导的Majorana涡流模式和Majorana抗变量模式具有不同的能量和空间分辨状态的特征。
In the present study topologically nontrivial edge and vortex bound states are described in the coexistence phase of chiral spin-singlet superconductivity and noncollinear spin ordering on a triangular lattice in the presence of few (up to four) vortices. We consider the topological phase transition induced by the magnetic order between the phase hosting Majorana modes and the initial phase of the chiral d-wave superconductivity supporting non-Majorana modes which is also topologically nontrivial. The change of the excitation spectrum at the critical point is obtained in both cases of open and periodic boundary conditions in the presence of vortices. It is proved that zero energy Majorana modes localized at vortex cores are caused by noncollinear long-range magnetic ordering. Even though nearby excitation energies of subgap states including the edge-localized and vortex-localized states are very close to each other, the energy difference between different vortex bound states is an order of magnitude higher. This difference determines the energy gap for Majorana vortex modes separating them from other vortex bound states. It is found that even in the presence of noncollinear spin ordering its value can be estimated from the excitation energy of vortex bound states in the pure chiral d-wave state for the nonmagnetic case. By studying local density of states near the vortex cores the possibility to experimentally detect the described Majorana vortex modes by scanning tunneling microscopy is discussed. It is demonstrated that Majorana vortex modes and Majorana antivortex modes induced by noncollinear magnetism have different features in energy and spatially resolved density of states due to the chiral symmetry on the superconducting order parameter.
