Selective area epitaxy of PbTe-Pb hybrid nanowires on a lattice-matched substrate
Selective area epitaxy of PbTe-Pb hybrid nanowires on a lattice-matched substrate
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DOI：
10.1103/physrevmaterials.6.034205
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发表时间：
2022-03-23
影响因子：
3.4
通讯作者：
He, Ke
中科院分区：
文献类型：
--
作者：
Jiang, Yuying;Yang, Shuai;He, Ke
拓扑量子计算是基于对拓扑量子比特编码的Majorana零模进行编织的。半导体-超导体混合纳米线是实现Majorana零模的一种很有前途的候选平台。拓扑量子比特和编织操作的实现需要可扩展和无序的纳米线网络。平面内InAs和InSb纳米线的选择性面积生长，以及超导结构的阴影壁生长，通过实现各种网络结构，展示了这种可扩展性。然而，纳米线-衬底界面明显的晶格失配，作为无序源，在这一路线图上施加了严重的障碍。在这里，结合选择性区域和影壁生长，我们展示了在几乎完全晶格匹配的衬底上制备PbTe-Pb杂化纳米线-另一个有潜力的Majorana系统-所有这些都在一个分子束外延室中完成。透射电子显微镜显示了PbTe纳米线的单晶性质，以及它与CdTe衬底和铅覆盖层的原子锐利和干净的界面，没有明显的相互扩散或应变。接近理想的界面条件，加上PbTe的高介电常数对电荷杂质的强屏蔽，有望成为研究Majorana零模和拓扑量子计算的清洁纳米线系统。
Topological quantum computing is based on the braiding of Majorana zero modes encoding topological qubits. A promising candidate platform for Majorana zero modes is semiconductor-superconductor hybrid nanowires. The realization of topological qubits and braiding operations requires scalable and disorder-free nanowire networks. Selective area growth of in-plane InAs and InSb nanowires, together with shadow-wall growth of superconductor structures, have demonstrated this scalability by achieving various network structures. However, the noticeable lattice mismatch at the nanowire-substrate interface, acting as a disorder source, imposes a serious obstacle along with this road map. Here, combining selective area and shadow-wall growth, we demonstrate the fabrication of PbTe-Pb hybrid nanowires-another potentially promising Majorana system-on a nearly perfectly lattice-matched substrate CdTe, all done in one molecular beam epitaxy chamber. Transmission electron microscopy shows the single-crystal nature of the PbTe nanowire and its atomically sharp and clean interfaces to the CdTe substrate and Pb overlayer, without noticeable interdiffusion or strain. The nearly ideal interface condition, together with the strong screening of charge impurities due to the large dielectric constant of PbTe, holds promise towards a clean nanowire system to study Majorana zero modes and topological quantum computing.