In a hybrid system of topological insulator (TI)/superconductor (SC), the proximity-induced topological superconductivity is expected to appear at the interface. Here we propose and demonstrate that a TI/SC hybrid Bi₂Te₃/PdTe₂ heterostructure serves as a platform for exploring topological superconductivity with various features: all made of tellurium compounds, epitaxial growth, and a small charge transfer interface. In the Bi₂Te₃/PdTe₂ heterostructure films, we observe large nonreciprocal charge transport near the superconducting transition temperature under a transverse in-plane magnetic field. The observation indicates the interplay between the topological surface state and superconductivity, suggesting that the Bi₂Te₃/PdTe₂ heterostructure is a candidate for a topological superconductor. Also observed is an unexpected sign reversal of the nonreciprocal coefficient when the in-plane magnetic field is slightly tilted toward the out-of-plane direction. The analysis reveals that the sign reversal occurs with the change of dominant vortex type, that is, the change from spontaneous vortices to external-field induced ones.

在拓扑绝缘体（TI）/超导体（SC）的混合系统中，接近诱导的拓扑超导性有望出现在界面处。在这里，我们提出并证明了 TI/SC 混合 Bi ₂ Te ₃ /PdTe ₂异质结构可作为探索具有各种特征的拓扑超导性的平台：全部由碲化合物制成、外延生长和小电荷转移界面。在 Bi ₂ Te ₃ /PdTe ₂异质结构薄膜，我们观察到在横向平面内磁场下超导转变温度附近的大单向电荷传输。观察结果表明拓扑表面态和超导性之间的相互作用，表明Bi ₂ Te ₃ /PdTe ₂异质结构是拓扑超导体的候选者。当面内磁场略微向面外方向倾斜时，还观察到非互易系数的意外符号反转。分析表明，随着主导涡类型的变化，即从自发涡向外场诱导涡的变化，出现了符号反转。