Majorana oscillations modulated by Fano interference and degree of nonlocality in a topological superconducting-nanowire–quantum-dot system
Majorana oscillations modulated by Fano interference and degree of nonlocality in a topological superconducting-nanowire–quantum-dot system
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DOI：
10.1103/physrevb.98.075142
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发表时间：
2018-02
影响因子：
3.7
通讯作者：
L. S. Ricco;V. L. Campo;I. Shelykh;A. Seridonio
中科院分区：
文献类型：
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作者：
L. S. Ricco;V. L. Campo;I. Shelykh;A. Seridonio
我们从理论上探讨了Fano干涉在所谓的马约拉纳振荡中的影响，在T形的混合设置形成的量子点（QD）之间放置的导电引线和侧耦合到拓扑超导纳米线（TSNW）托管零能量马约拉纳束缚态（MBSs）的两端。微分电导作为外部磁场的函数揭示了振荡行为。振荡的形状和幅度都取决于偏置电压、MBS非局域性程度和系统的Fano参数，这些参数决定了干扰的状态。当后者是这样的，直接铅-铅路径主导的铅-QD-铅路径和偏压调谐在谐振与QD零能量，明显的分数Fano共振周围观察到高度非本地几何零偏置。此外，作为偏置电压和量子点能级的函数的电导曲线显示“蝴蝶结”和“钻石”形状，与先前的理论和实验工作定性一致。这些发现确保我们的建议可以用来估计MBS非局部性的程度，从而允许调查其拓扑性质。
We explore theoretically the influence of Fano interference in the so-called Majorana oscillations in a T-shaped hybrid setup formed by a quantum dot (QD) placed between conducting leads and side-coupled to a topological superconducting nanowire (TSNW) hosting zero-energy Majorana bound states (MBSs) at the ends. Differential conductance as a function of the external magnetic field reveals oscillatory behavior. Both the shape and amplitude of the oscillations depend on the bias-voltage, degree of MBSs non-locality and Fano parameter of the system determining the regime of interference. When the latter is such that direct lead-lead path dominates over lead-QD-lead path and the bias is tuned in resonance with QD zero-energy, pronounced fractional Fano-like resonances are observed around zero-bias for highly non-local geometries. Further, the conductance profiles as a function of both bias-voltage and QD energy level display "bowtie" and "diamond" shapes, in qualitative agreement with both previous theoretical and experimental works. These findings ensure that our proposal can be used to estimate the degree of MBS non-locality, thus allowing to investigate their topological properties.