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arXiv 2209.07280cond-mat.supr-concond-mat.mtrl-scicond-mat.str-el
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MnTe/Bi2Te3/Fe(Te,Se)三层异质结中强零能态和超导能隙的观测

Observation of robust zero-energy state and enhanced superconducting gap in a tri-layer heterostructure of MnTe/Bi2Te3/Fe(Te, Se)

Shuyue Ding, Chen Chen, Zhipeng Cao, Di Wang, Yongqiang Pan, Ran Tao, Dongming Zhao, Yining Hu, Tianxing Jiang, Yajun Yan, Zhixiang Shi, Xiangang Wan, Donglai Feng, Tong Zhang

摘要:

磁性材料和超导体之间的界面长期以来一直被预测具有非常规的超导性,例如自旋三重态配对和拓扑非平凡配对状态,特别是当引入自旋轨道耦合(SOC)时。为了识别这些新的配对状态,制造包含这些各种属性的同质异质结构是优选的,但通常具有挑战性。本文合成了MnTe/Bi_2Te_3/Fe(Te,Se)三层结构的范德华异质结,结合了s波超导性、厚度相关磁性和强SOC,通过低温扫描隧道显微镜(STM)观察到MnTe单胞表面具有显著的非平凡特性和增强的超导能隙尺寸。相比之下,在2UC MnTe上没有观察到零能态。第一性原理计算进一步表明,1UC MnTe具有大的界面Dzyaloshinskiii-Moriya相互作用(Dzyaloshinskiii-Moriya interaction,Dzyaloshinskii-Moriya interaction)和受抑的AFM状态,这可能会促进非共线自旋织构。因此,它提供了一个很有前途的平台,探索拓扑非平凡超导。

英文摘要:

The interface between magnetic material and superconductors has long been predicted to host unconventional superconductivity, such as spin-triplet pairing and topological nontrivial pairing state, particularly when spin-orbital coupling (SOC) is incorporated. To identify these novel pairing states, fabricating homogenous heterostructures which contain such various properties are preferred, but often challenging. Here we synthesized a tri-layer type van-der Waals heterostructure of MnTe/Bi2Te3/Fe(Te, Se), which combined s-wave superconductivity, thickness dependent magnetism and strong SOC. Via low-temperature scanning tunneling microscopy (STM), we observed robust zero-energy states with notably nontrivial properties and an enhanced superconducting gap size on single unit-cell (UC) MnTe surface. In contrast, no zero-energy state was observed on 2UC MnTe. First-principle calculations further suggest the 1UC MnTe has large interfacial Dzyaloshinskii-Moriya interaction (DMI) and a frustrated AFM state, which could promote non-collinear spin textures. It thus provides a promising platform for exploring topological nontrivial superconductivity.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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