Superconducting Proximity Effect in InAsSb Surface Quantum Wells with In Situ Al Contacts
Superconducting Proximity Effect in InAsSb Surface Quantum Wells with In Situ Al Contacts
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DOI：
10.1021/acsaelm.0c00269
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发表时间：
2020-08-25
影响因子：
4.7
通讯作者：
Shabani, Javad
中科院分区：
文献类型：
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作者：
Mayer, William;Schiela, William F.;Shabani, Javad
我们在外延Al接触生长的InAs_(0.5)Sb_(0.5)量子阱中发现了很强的超导邻近效应，这对介观和拓扑超导电性具有重要意义。与通常研究较多的InAs和InSb半导体不同，块体InAs0.5Sb0.5支持更强的自旋-轨道耦合和更大的g因子。然而，这些潜在的理想性质以前没有在具有超导体的外延异质结构中被测量到，这可以作为容错拓扑量子计算的平台。通过结构和输运表征，我们观察到高质量的界面和强烈的自旋-轨道耦合。我们在InAs0.5Sb0.5量子阱的基础上制备了约瑟夫森结，观察到了很强的邻近效应。在接触间隔为500 nm的情况下，这些结的正常电阻R-N、临界电流I-c和过电流I-ex的产物IcRN=270微伏和IexRN=230微伏。这两个量都显示出与高度透明的接触的强大和远距离邻近效应。
We demonstrate a robust superconducting proximity effect in InAs0.5Sb0.5 quantum wells grown with epitaxial Al contacts, which has important implications for mesoscopic and topological superconductivity. Unlike more commonly studied InAs and InSb semiconductors, bulk InAs0.5Sb0.5 supports stronger spin-orbit coupling and a larger g-factor. However, these potentially desirable properties have not been previously measured in epitaxial heterostructures with superconductors, which could serve as a platform for fault-tolerant topological quantum computing. Through structural and transport characterization, we observe highquality interfaces and a strong spin-orbit coupling. We fabricate Josephson junctions based on InAs0.5Sb0.5 quantum wells and observe a strong proximity effect. With a contact separation of 500 nm, these junctions exhibit products IcRN = 270 mu V and IexRN = 230 mu V of normal resistance R-N, critical current I-c, and excess current I-ex. Both of these quantities demonstrate a robust and long-range proximity effect with highly transparent contacts.