Hard gap in epitaxial semiconductor-superconductor nanowires
Hard gap in epitaxial semiconductor-superconductor nanowires
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DOI：
10.1038/nnano.2014.306
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发表时间：
2015-03-15
影响因子：
38.3
通讯作者：
Marcus, C. M.
中科院分区：
文献类型：
--
作者：
Chang, W.;Albrecht, S. M.;Marcus, C. M.
超导性的许多现在和未来的应用将受益于载流子密度和隧穿速率的静电控制，这是半导体器件的标志。一个特别令人兴奋的应用是实现拓扑超导性（1）作为量子信息处理的基础（2，3）。基于半导体纳米线中的邻近效应的这一方向的提议是有吸引力的，因为关键成分目前在手中（4，5）。然而，先前的近似半导体的例子显示出超导能隙以下的显著隧穿电导，表明子能隙状态的连续性-这种情况使拓扑保护无效（6，7）。在这里，我们报告了一个硬超导间隙诱导的邻近效应在半导体中，使用外延InAs-Al超导体超导体纳米线。硬间隙，加上有利的材料性能和栅极可调性，使这个新的混合系统有吸引力的一些应用，以及介观超导的基础研究。
Many present and future applications of superconductivity would benefit from electrostatic control of carrier density and tunnelling rates, the hallmark of semiconductor devices. One particularly exciting application is the realization of topological superconductivity(1) as a basis for quantum information processing(2,3). Proposals in this direction based on the proximity effect in semiconductor nanowires are appealing because the key ingredients are currently in hand(4,5). However, previous instances of proximitized semiconductors show significant tunnelling conductance below the superconducting gap, suggesting a continuum of subgap states-a situation that nullifies topological protection(6,7). Here, we report a hard superconducting gap induced by the proximity effect in a semiconductor, using epitaxial InAs-Al semiconductor-superconductor nanowires. The hard gap, together with favourable material properties and gate-tunability, makes this new hybrid system attractive for a number of applications, as well as fundamental studies of mesoscopic superconductivity.