论文标题
锗中的平面约瑟夫森连接：立方旋转轨道相互作用的效果
Planar Josephson junctions in germanium: Effect of cubic spin-orbit interaction
论文作者
论文摘要
平面约瑟夫森连接处，包括具有强旋转轨道相互作用（SOI）的半导体，是托管Majorana绑定状态（MBS）的有前途的平台。在平面约瑟夫森连接处的MBS上的先前作品集中在电子气体上，SOI在动量中是线性的。相比之下，平面锗（GE）中的二维孔气体表现出在动量中是立方体的SOI。但是，我们在这里表明，由于特别大的SOI，GE是一种有利的材料。使用离散的模型，我们数值模拟了GE平面Josephson交界处，并证明了Cubic SOI也可以导致MBS的出现。有趣的是，我们发现立方SOI产生不对称相图，这是整个连接中超导相位差的函数。我们还发现，微不足道的Andreev结合状态可以模仿GE Planar Josephson交界处MBS的特征，因此使MBSS的实验检测变得困难。我们使用实验现实的参数来评估在实验限制中是否可以访问拓扑阶段。我们的分析表明，二维GE是拓扑阶段的吉祥候选者。
Planar Josephson junctions comprising semiconductors with strong spin-orbit interaction (SOI) are promising platforms to host Majorana bound states (MBSs). Previous works on MBSs in planar Josephson junctions have focused on electron gases, where SOI is linear in momentum. In contrast, a two-dimensional hole gas in planar germanium (Ge) exhibits SOI that is cubic in momentum. Nevertheless, we show here that due to the particularly large SOI, Ge is a favorable material. Using a discretized model, we numerically simulate a Ge planar Josephson junction and demonstrate that also cubic SOI can lead to the emergence of MBSs. Interestingly, we find that the cubic SOI yields an asymmetric phase diagram as a function of the superconducting phase difference across the junction. We also find that trivial Andreev bound states can imitate the signatures of MBSs in a Ge planar Josephson junction, therefore making the experimental detection of MBSs difficult. We use experimentally realistic parameters to assess if the topological phase is accessible within experimental limitations. Our analysis shows that two-dimensional Ge is an auspicious candidate for topological phases.
