论文标题
Andreev Bound State的非本地运输签名
Nonlocal transport signatures of Andreev bound states
论文作者
论文摘要
在本博士学位论文中，研究了基于基于分子梁外延的量子设备，并研究了具有原位生长外延膜的Inas半导体。实现了新的装置几何形状，可以研究由于存在自旋轨道耦合，Zeeman效应和超导接近效应而导致的半导体纳米线中低温下出现的结合状态。提出了利用二维异质结构中的栅极定义的纳米线的实验，或者呈现了带有AL的全壳的蒸气 - 液体 - 固体生长的纳米线。开发了设备和实验方法，可在纳米线的多个位置进行隧道光谱。讨论了Andreev结合状态的非本地电导传输测量结果。由于其扩展的波函数，与量子点在邻近测量位置的隧道光谱中显示了局部杂交的结合状态。如果相邻的隧道测量位置之间的距离大于0.8 $ \ mathrm {μm} $，则没有观察到扩展结合状态的签名。
In this PhD thesis, quantum devices based on molecular-beam epitaxy grown InAs semiconductor with an in-situ grown epitaxial Al film were investigated. Novel device geometries were realized that allow for the study of bound states that emerge at low temperatures in semiconducting nanowires due to the presence of spin-orbit coupling, Zeeman effect, and superconducting proximity effect. Experiments utilizing either gate-defined nanowires in two-dimensional heterostructures or vapor-liquid-solid grown nanowires with a full-shell of Al are presented. Devices and experimental methods were developed that allow for tunneling spectroscopy at multiple locations of a nanowire. Results of nonlocal conductance transport measurements of Andreev bound states are discussed. Due to their extended wavefunction, bound states that are locally hybridized with a quantum dot show characteristic signatures in tunneling spectroscopy at neighboring measurement locations. If the distance between neighboring tunneling measurement locations is larger than 0.8 $\mathrm{μm}$ no signatures of extended bound states was observed.
