论文标题
在MNTE/BI2TE3/FE（TE，SE）的三层异质结构中观察强大的零能状态和增强的超导差距
Observation of robust zero-energy state and enhanced superconducting gap in a tri-layer heterostructure of MnTe/Bi2Te3/Fe(Te, Se)
论文作者
论文摘要
长期以来，磁性材料和超导体之间的界面已被预测为具有非常规的超导性，例如自旋三型配对和拓扑非平凡配对状态，尤其是当旋转轨道耦合（SOC）纳入时。为了识别这些新型的配对状态，可以优选包含各种特性的同质异质结构，但通常具有挑战性。在这里，我们合成了MNTE/BI2TE3/Fe（TE，SE）的三层型Van-waals异质结构，该结构结合了S波超导性，依赖厚度的磁性和强烈的SOC。通过低温扫描隧道显微镜（STM），我们观察到具有明显非平凡特性的稳健零能量状态，并且在单个单位细胞（UC）MNTE表面上具有增强的超导间隙大小。相比之下，在2uc MNTE上未观察到零能量。第一原则计算进一步表明1UC MNTE具有较大的界面Dzyaloshinskii-Moriya相互作用（DMI）和沮丧的AFM状态，可以促进非类别的自旋纹理。因此，它为探索拓扑非平凡的超导性提供了一个有希望的平台。
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.
