Magnetic field resistant quantum interferences in Josephson junctions based on bismuth nanowires
Magnetic field resistant quantum interferences in Josephson junctions based on bismuth nanowires
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DOI：
10.1103/physrevb.90.245427
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发表时间：
2014-12-23
影响因子：
3.7
通讯作者：
Bouchiat, H.
中科院分区：
文献类型：
--
作者：
Li, Chuan;Kasumov, A.;Bouchiat, H.
我们研究了与超导电极连接的微米长的铋纳米线在高临界场下的邻近诱导超导性。在低温下，我们测量到在与电极临界磁场（高于11t）一样高的磁场中持续存在的超电流。临界电流也受到磁场的强烈调制。在某些样品中，我们发现规则的，快速的鱿鱼状周期性振荡发生在高场。其他样品在特斯拉场尺度上表现出较少的周期性但充分的临界电流调制，具有场引起的超电流消失。这些发现表明样品中存在低维、相位相干、干扰的导电区，轨道和自旋贡献之间存在微妙的相互作用。我们将这些惊人的结果与铋表面态的电子性质、强Rashba自旋-轨道耦合、大的有效g因子及其对诱导对相关的影响联系起来。特别是，我们强调纳米线的特定方面的拓扑边缘状态的可能贡献。
We investigate proximity-induced superconductivity in micrometer-long bismuth nanowires connected to superconducting electrodes with a high critical field. At low temperature we measure a supercurrent that persists in magnetic fields as high as the critical field of the electrodes (above 11 T). The critical current is also strongly modulated by the magnetic field. In certain samples we find regular, rapid SQUID-like periodic oscillations occurring up to high fields. Other samples exhibit less periodic but full modulations of the critical current on Tesla field scales, with field-caused extinctions of the supercurrent. These findings indicate the existence of low dimensionality, phase coherent, interfering conducting regions through the samples, with a subtle interplay between orbital and spin contributions. We relate these surprising results to the electronic properties of the surface states of bismuth, strong Rashba spin-orbit coupling, large effective g factors, and their effect on the induced pair correlations. In particular, we emphasize the possible contribution of topological edge states of specific facets of the nanowires.