Peter Grünberg Institute (PGI-9) and JARA-Fundamentals of Future Information Technology, Forschungszentrum Jülich GmbH , 52425 Jülich, Germany.
Nano Lett. 2014 Nov 12;14(11):6269-74. doi: 10.1021/nl502598s. Epub 2014 Oct 21.
The magnetotransport of GaAs/InAs core/shell nanowires contacted by two superconducting Nb electrodes is investigated, where the InAs shell forms a tube-like conductive channel around the highly resistive GaAs core. By applying a magnetic field along the nanowire axis, regular magnetoconductance oscillations with an amplitude in the order of e(2)/h are observed. The oscillation amplitude is found to be larger by 2 orders of magnitude compared to the measurements of a reference sample with normal metal contacts. For the Nb-contacted core/shell nanowire the oscillation period corresponds to half a flux quantum Φ0/2 = h/2e in contrast to the period of Φ0 of the reference sample. The strongly enhanced magnetoconductance oscillations are explained by phase-coherent resonant Andreev reflections at the Nb-core/shell nanowire interface.
研究了由两个超导 Nb 电极接触的 GaAs/InAs 核/壳纳米线的磁输运，其中 InAs 壳在高阻 GaAs 核周围形成管状导电通道。通过沿纳米线轴施加磁场，观察到幅度在 e(2)/h 量级的规则磁电导振荡。与具有正常金属接触的参考样品的测量相比，发现振荡幅度大了 2 个数量级。对于 Nb 接触的核/壳纳米线，振荡周期对应于半个磁通量子 Φ0/2 = h/2e，与参考样品的 Φ0 周期相反。通过在 Nb-核/壳纳米线界面处的相干共振安德烈夫反射，强烈增强了磁电导振荡。
