Using the superconducting proximity effect for engineering a topological superconducting state in a topological insulator (TI) is a promising route to realize Majorana fermions. However, epitaxial growth of a superconductor on the TI surface to achieve a good proximity effect has been a challenge. We discovered that simply depositing Pd on thin films of the TI material ${\left({\mathrm{Bi}}_{1-x}{\mathrm{Sb}}_x\right)}_2{\mathrm{Te}}_3$ leads to an epitaxial self-formation of $\mathrm{Pd}{\mathrm{Te}}_2$ superconductor having the superconducting transition temperature of $\sim 1$ K. This self-formed superconductor proximitizes the TI, which is confirmed by the appearance of a supercurrent in Josephson-junction devices made on ${\left({\mathrm{Bi}}_{1-x}{\mathrm{Sb}}_x\right)}_2{\mathrm{Te}}_3$. This self-epitaxy phenomenon can be conveniently used for fabricating TI-based superconducting nanodevices to address the superconducting proximity effect in TIs.

中文翻译：

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在拓扑绝缘体（Bi1-xSbx）2Te3中诱导超导的新型自外延

利用超导邻近效应在拓扑绝缘体（TI）中工程化拓扑超导状态是实现马里亚纳费米子的有前途的途径。然而，为了获得良好的邻近效应，在TI表面上外延生长超导体一直是一个挑战。我们发现只需将Pd沉积在TI材料的薄膜上${（{双}_{\mathrm{1个}-X}{锑}_X）}_2{特}_3$ 导致外延自形成 $钯{特}_2$ 超导体的超导转变温度为 $〜\mathrm{1个}$ K.这种自形成的超导体可以替代TI，这可以通过在制造的约瑟夫森结器件中出现超电流来证实。 ${（{双}_{\mathrm{1个}-X}{锑}_X）}_2{特}_3$。这种自外延现象可以方便地用于制造基于TI的超导纳米器件，以解决TI中的超导邻近效应。