论文标题
在耦合量子点中实现最小的基塔夫链
Realization of a minimal Kitaev chain in coupled quantum dots
论文作者
论文摘要
Majorana Bound国家构成了凝结物理学中新兴非阿布尔激发的最简单例子之一。基塔耶夫(Kitaev)提出的一种玩具模型表明,这种状态可以在无旋转$ p $波的超导链的末端出现。实现其实现的实用建议需要通过电子隧道和跨越Andreev反射在链中耦合相邻的量子点。尽管在半导体纳米线和碳纳米管中都观察到了这两个过程,但交叉的Andreev相互作用既不容易调谐,也不足够强,无法诱导点状态的相干杂交。在这里,我们证明了人造Kitaev链的所有必要成分同时存在:在INSB纳米线中的两个自旋极化量子点,与弹性共同接合和交叉Andreev反射强烈耦合。我们将该系统微调到一个最佳地点,预计一对穷人的主要国家将出现。在这个最佳位置,运输特征满足了对这种系统的理论预测,包括对局部扰动的成对相关性,零电荷和稳定性。虽然可以缩放此处介绍的简单系统以模拟具有新兴拓扑秩序的完整基塔夫链,但它也可以直接使用它来探索与非亚伯式的任何人有关的相关物理学。
Majorana bound states constitute one of the simplest examples of emergent non-Abelian excitations in condensed matter physics. A toy model proposed by Kitaev shows that such states can arise at the ends of a spinless $p$-wave superconducting chain. Practical proposals for its realization require coupling neighboring quantum dots in a chain via both electron tunneling and crossed Andreev reflection. While both processes have been observed in semiconducting nanowires and carbon nanotubes, crossed-Andreev interaction was neither easily tunable nor strong enough to induce coherent hybridization of dot states. Here we demonstrate the simultaneous presence of all necessary ingredients for an artificial Kitaev chain: two spin-polarized quantum dots in an InSb nanowire strongly coupled by both elastic co-tunneling and crossed Andreev reflection. We fine-tune this system to a sweet spot where a pair of Poor Man's Majorana states is predicted to appear. At this sweet spot, the transport characteristics satisfy the theoretical predictions for such a system, including pairwise correlation, zero charge and stability against local perturbations. While the simple system presented here can be scaled to simulate a full Kitaev chain with an emergent topological order, it can also be used imminently to explore relevant physics related to non-Abelian anyons.