论文标题
透明的可盖超导阴影连接
Transparent Gatable Superconducting Shadow Junctions
论文作者
论文摘要
栅极可调连接是基于混合半导体 - 渗透材料的量子设备中的关键要素。它们具有从隧道光谱探针到盖森和拓扑台的电压控制量子操作的多种用途。所有人的共同点是，连接透明度起着至关重要的作用。在这项研究中，我们种植了单晶INA，INSB和$ \ MATHRM {inas_ {1-x} sb_x} $纳米线，具有外在超导体和位于原位的阴影连接处，并在单步分子束外观过程中。我们研究了连接处的制造参数，连接形态和电子传输特性之间的相关性，并表明所检查的原位阴影连接质量明显高于蚀刻连接的质量。通过改变阴影连接的边缘清晰度，我们表明最锐利的边缘对所有三个检查的半导体产生了最高的连接透明度。此外，关键的超电流测量结果显示出一个非常高的$ i_ \ mathrm {c} r_ \ mathrm {n} $，靠近ko $ - $ 2 $ 2限制。这项研究表明，通往可靠的闸门可靠超导量子的有前途的工程路径。
Gate tunable junctions are key elements in quantum devices based on hybrid semiconductor-superconductor materials. They serve multiple purposes ranging from tunnel spectroscopy probes to voltage-controlled qubit operations in gatemon and topological qubits. Common to all is that junction transparency plays a critical role. In this study, we grow single crystalline InAs, InSb and $\mathrm{InAs_{1-x}Sb_x}$ nanowires with epitaxial superconductors and in-situ shadowed junctions in a single-step molecular beam epitaxy process. We investigate correlations between fabrication parameters, junction morphologies, and electronic transport properties of the junctions and show that the examined in-situ shadowed junctions are of significantly higher quality than the etched junctions. By varying the edge sharpness of the shadow junctions we show that the sharpest edges yield the highest junction transparency for all three examined semiconductors. Further, critical supercurrent measurements reveal an extraordinarily high $I_\mathrm{C} R_\mathrm{N}$, close to the KO$-$2 limit. This study demonstrates a promising engineering path towards reliable gate-tunable superconducting qubits.
