Epitaxial Pb on InAs nanowires for quantum devices
Epitaxial Pb on InAs nanowires for quantum devices
复制标题
量子器件用InAs纳米线上的外延铅
DOI：
10.1038/s41565-021-00900-9
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发表时间：
2021-05-10
影响因子：
38.3
通讯作者：
Nygard, Jesper
中科院分区：
文献类型：
--
作者：
Kanne, Thomas;Marnauza, Mikelis;Nygard, Jesper
半导体-超导体混合体用于实现复杂的量子现象，但在可接近的磁场和温度范围内受到限制。现在，由InAs纳米线和外延匹配的、单晶的、原子级平坦的Pb薄膜制成的混合器件呈现出上级优越的特性，使可用的参数空间增加了一倍，半导体-超导体混合器件被广泛用于实现复杂的量子现象，如拓扑超导和自旋耦合到库珀对。在高磁场和不断增加的工作温度下，新的、奇异的制度需要新的、外延匹配的超导体-超导体材料。一个挑战是为具有所需性质的材料之间的异质结构形成创造有利条件。在这里，我们利用金属半导体生长的知识增加开发InAs纳米线与外延匹配，单晶，原子级平坦的铅膜，没有轴向晶界。这些高度有序的异质结构具有7 K的临界温度和1.25 meV的超导能隙，其在8.5 T下仍然很硬，因此它们提供的参数空间是替代超导体-超导体混合体的参数空间的两倍多。此外，InAs/Pb岛器件表现出从库珀对到单电子充电的磁场驱动转变，这是用于拓扑量子计算的先决条件。半导体-铅混合物有可能使许多不同的量子系统进入全新的状态。
Semiconductor-superconductor hybrids are used for realizing complex quantum phenomena but are limited in the accessible magnetic field and temperature range. Now, hybrid devices made from InAs nanowires and epitaxially matched, single-crystal, atomically flat Pb films present superior characteristics, doubling the available parameter space.Semiconductor-superconductor hybrids are widely used to realize complex quantum phenomena, such as topological superconductivity and spins coupled to Cooper pairs. Accessing new, exotic regimes at high magnetic fields and increasing operating temperatures beyond the state-of-the-art requires new, epitaxially matched semiconductor-superconductor materials. One challenge is the generation of favourable conditions for heterostructural formation between materials with the desired properties. Here we harness an increased knowledge of metal-on-semiconductor growth to develop InAs nanowires with epitaxially matched, single-crystal, atomically flat Pb films with no axial grain boundaries. These highly ordered heterostructures have a critical temperature of 7 K and a superconducting gap of 1.25 meV, which remains hard at 8.5 T, and therefore they offer a parameter space more than twice as large as those of alternative semiconductor-superconductor hybrids. Additionally, InAs/Pb island devices exhibit magnetic field-driven transitions from a Cooper pair to single-electron charging, a prerequisite for use in topological quantum computation. Semiconductor-Pb hybrids potentially enable access to entirely new regimes for a number of different quantum systems.