Measuring Majorana nonlocality and spin structure with a quantum dot
Measuring Majorana nonlocality and spin structure with a quantum dot
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DOI：
10.1103/physrevb.96.085418
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发表时间：
2017-08-11
影响因子：
3.7
通讯作者：
San-Jose, Pablo
中科院分区：
文献类型：
--
作者：
Prada, Elsa;Aguado, Ramon;San-Jose, Pablo
具有邻近感应超导性的半导体纳米线中鲁棒的零偏置输运异常已在各种实验中得到令人信服的证明。虽然这些与纳米线末端马约拉纳零模式的存在兼容，但现在需要直接证明它们的非局域性和拓扑保护。在这里，我们表明，纳米线末端的量子点可以用作强大的光谱工具，通过局域传输测量来量化马约拉纳非局域性程度。此外，库仑封锁状态下单重态-双重态跃迁处的点子能隙态的自旋极化允许点直接探测马约拉纳波函数的自旋结构并间接测量纳米线的自旋轨道耦合。
Robust zero-bias transport anomalies in semiconducting nanowires with proximity-induced superconductivity have been convincingly demonstrated in various experiments. While these are compatible with the existence of Majorana zero modes at the ends of the nanowire, a direct proof of their nonlocality and topological protection is now needed. Here we show that a quantum dot at the end of the nanowire may be used as a powerful spectroscopic tool to quantify the degree of Majorana nonlocality through a local transport measurement. Moreover, the spin polarization of dot subgap states at singlet-doublet transitions in the Coulomb blockade regime allows the dot to directly probe the spin structure of the Majorana wave function and indirectly measure the spin-orbit coupling of the nanowire.