Crossover from Ising- to Rashba-type superconductivity in epitaxial Bi2Se3/monolayer NbSe2 heterostructures
Crossover from Ising- to Rashba-type superconductivity in epitaxial Bi2Se3/monolayer NbSe2 heterostructures
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DOI：
10.1038/s41563-022-01386-z
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发表时间：
2021-12
期刊：
影响因子：
41.2
通讯作者：
H. Yi;Lunhui Hu;Yuanxi Wang;Run Xiao;Jiaqi Cai;D. R. Hickey;C. Dong;Yi-Fan Zhao;Lingjie Zhou;Ruoxi Zhang;A. Richardella;N. Alem;J. Robinson;M. Chan;Xiaodong Xu;N. Samarth;Chaoxing Liu;Cui-Zu Chang
中科院分区：
文献类型：
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作者：
H. Yi;Lunhui Hu;Yuanxi Wang;Run Xiao;Jiaqi Cai;D. R. Hickey;C. Dong;Yi-Fan Zhao;Lingjie Zhou;Ruoxi Zhang;A. Richardella;N. Alem;J. Robinson;M. Chan;Xiaodong Xu;N. Samarth;Chaoxing Liu;Cui-Zu Chang
与 ans-wave 超导体连接的拓扑绝缘体 (TI) 预计将具有拓扑超导性。尽管波超导体外延TI薄膜的生长已经通过分子束外延实现，但对于合成原子薄TI/超导体异质结构仍然是一个突出的挑战，这对于设计拓扑超导相至关重要。在这里，我们使用分子束外延在单层 NbSe2 上生长厚度受控的 Bi2Se3 薄膜，并对这些异质结构进行原位角分辨光电子能谱和异位磁输运测量。我们发现，Rashba 型体量子阱带和自旋非简并表面态的出现与 Bi2Se3/单层 NbSe2 异质结构中超导面内上临界磁场的显着抑制相一致。这是伊辛型超导对与拉什巴型超导对交叉的标志，是通过改变 Bi2Se3 薄膜厚度引起的。我们的工作为探索 TI/Ising 超导异质结构中的稳健拓扑超导相开辟了一条途径。
A topological insulator (TI) interfaced with ans-wave superconductor has been predicted to host topological superconductivity. Although the growth of epitaxial TI films ons-wave superconductors has been achieved by molecular-beam epitaxy, it remains an outstanding challenge for synthesizing atomically thin TI/superconductor heterostructures, which are critical for engineering the topological superconducting phase. Here we used molecular-beam epitaxy to grow Bi2Se3films with a controlled thickness on monolayer NbSe2and performed in situ angle-resolved photoemission spectroscopy and ex situ magnetotransport measurements on these heterostructures. We found that the emergence of Rashba-type bulk quantum-well bands and spin-non-degenerate surface states coincides with a marked suppression of the in-plane upper critical magnetic field of the superconductivity in Bi2Se3/monolayer NbSe2heterostructures. This is a signature of a crossover from Ising- to Rashba-type superconducting pairings, induced by altering the Bi2Se3film thickness. Our work opens a route for exploring a robust topological superconducting phase in TI/Ising superconductor heterostructures.