论文标题
一维拓扑超导完全基于相控制
One-dimensional topological superconductivity based entirely on phase control
论文作者
论文摘要
一维的拓扑超导性需要时间交流对称性破裂，但与此同时，外部磁场会阻碍它。我们提供了一般的处方，用于在平面超导体 - 正常抗管物正常 - 正常 - 导管（SNSNS）约瑟夫森交界处诱导拓扑超导性，而无需在交界处施加任何磁场。我们的平台依靠两种关键成分：三个平行超导体形成两个带相绕组的SNS连接，而两个自旋分支的Fermi速度必须彼此不同。三个超导体之间的两个相差定义了一个参数平面，其中包括大拓扑区域。我们分析得出发生拓扑相变的临界曲线，并基于基于紧密结合模型的数值计算证实了结果。我们进一步提出了具有不平等的费米速度的材料平台，从而确立了我们方法的实验性可行性。
Topological superconductivity in one dimension requires time-reversal symmetry breaking, but at the same time it is hindered by external magnetic fields. We offer a general prescription for inducing topological superconductivity in planar superconductor-normal-superconductor-normal-superconductor (SNSNS) Josephson junctions without applying any magnetic fields on the junctions. Our platform relies on two key ingredients: the three parallel superconductors form two SNS junctions with phase winding, and the Fermi velocities for the two spin branches transverse to the junction must be different from one another. The two phase differences between the three superconductors define a parameter plane which includes large topological regions. We analytically derive the critical curves where the topological phase transitions occur, and corroborate the result with a numerical calculation based on a tight-binding model. We further propose material platforms with unequal Fermi velocities, establishing the experimental feasibility of our approach.
