AI 中文总结
本文预测在具有3重或6重旋转对称性的拓扑绝缘体的超导涡旋中存在稳定的环形马约拉纳模式，其源于特定狄拉克锥上的手性超导性，相关发现为拓扑超导研究提供了新视角。
AI 中文摘要
当拓扑绝缘体的表面态变为超导态时，可获得拓扑超导性，表面上的每个涡旋会容纳一个单一的马约拉纳零能模式，该模式通常是在涡旋核外呈指数衰减的波包。本文中，我们预测在具有3重或6重旋转对称性的拓扑绝缘体的超导涡旋中，存在稳定的环形马约拉纳零能模式，其波函数为环形，被称为环形马约拉纳模式。这类拓扑绝缘体的特征在于，在表面布里渊区的$\bar{\text{\u0393}}$点处有一个非线性狄拉克锥，或在$\bar{\text{M}}$点处有三个线性狄拉克锥。环形马约拉纳模式的起源，在前一种情况中是$\bar{\text{\u0393}}$点处非线性狄拉克锥上的有效手性f波超导性，在后一种情况中是三个线性狄拉克锥上的有效手性p波超导性的干涉。在两种情况中，环形马约拉纳模式均由旋转对称性和表面态携带的绕数3所稳定。我们预测了支持环形马约拉纳模式的候选材料，本研究为超导拓扑绝缘体中的拓扑超导性提供了新的见解。
英文摘要
When the surface states of a topological insulator becomes superconducting, topological superconductivity can be obtained, and each vortex on the surface can host one single Majorana zero-energy mode which is usually a wave packet decaying exponentially off the vortex core. Here, we predict stable Majorana zero-energy mode whose wave function is ring-shape, dubbed as annular Majorana mode, in the superconducting vortex in topological insulators respecting $3$-fold or $6$-fold rotational symmetry. Such topological insulators are featured with a single nonlinear Dirac cone located at $\barΓ$ or three linear Dirac cones at $\bar{\text{M}}$ in the surface Brillouin zone. The annular Majorana mode originates from the effective chiral $f$-wave superconductivity on the nonlinear Dirac cone in the former case and the interference of the effective chiral $p$-wave superconductivity on the three linear Dirac cones in the latter. In both cases, the annular Majorana mode is stabilized by the rotational symmetry and the winding number $3$ carried by the surface states. Candidate materials supporting the annular Majorana mode are predicted. Our work provides new insights into the topological superconductivity in superconducting topological insulators.
