超导边缘接触至埋藏锗量子阱
Superconducting edge contact to a buried Ge quantum well
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中文总结 AI 辅助
本文提出结合干湿法刻蚀的边缘接触方法，实现高质量超导接触至深埋锗量子阱，约瑟夫森结透明度近统一，量子点接触安德烈耶夫增强，第一平台接近4e^2/h，并展示量子化超电流。
中文摘要 AI 辅助
半导体-超导体混合系统构成了多种量子现象的基础，例如安德烈耶夫束缚态、拓扑超导性和混合量子霍尔态。这些混合系统的性能可极大受益于具有深埋量子阱的异质结构的卓越电子特性。然而，建立高质量的超导接触至此类量子阱仍具挑战性。在此，我们通过一种边缘接触方法解决此问题，该方法结合了各向异性干法刻蚀以接触量子阱，随后进行湿法刻蚀以制备界面。使用此方法制备的约瑟夫森结一致表现出接近统一的界面透明度，而量子点接触显示出强烈的安德烈耶夫增强，第一导电平台接近$4e^2/h$，即完美安德烈耶夫反射的极限。在超导量子点接触中，高接触质量进一步通过量子化超电流体现。这些结果确立了干法和湿法刻蚀的组合作为将深埋量子阱集成到超导混合器件中的稳健策略。
英文摘要
Semiconductor-superconductor hybrid systems form the basis for a broad range of quantum phenomena, such as Andreev bound states, topological superconductivity, and hybrid quantum Hall states. The performance of these hybrid systems can strongly benefit from the exceptional electronic properties of heterostructures with deeply buried quantum wells. However, establishing high-quality superconducting contacts to such quantum wells remains challenging. Here, we address this problem with an edge-contact approach that combines anisotropic dry etching to access the quantum well followed by wet etching for interface preparation. Josephson junctions fabricated using this approach consistently exhibit near-unity interface transparency, while quantum point contacts show strong Andreev enhancement, with the first conductance plateau approaching $4e^2/h$, the limit of perfect Andreev reflection. In superconducting quantum point contacts, the high contact quality is further manifested by quantized supercurrent. These results establish the combination of dry and wet etching as a robust strategy for integrating deeply buried quantum wells into superconducting hybrid devices.
发表机构
- Institute of Science and Technology Austria（奥地利科学技术研究所）
- Delft University of Technology（代尔夫特理工大学）
机构由 AI 辅助整理，请以论文原文为准。
