Borsoi Francesco, Zuo Kun, Gazibegovic Sasa, Op Het Veld Roy L M, Bakkers Erik P A M, Kouwenhoven Leo P, Heedt Sebastian
QuTech and Kavli Institute of Nanoscience, Delft University of Technology, GA Delft, 2600, The Netherlands.
RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama, 351-0198, Japan.
Nat Commun. 2020 Jul 22;11(1):3666. doi: 10.1038/s41467-020-17461-5.
Detecting the transmission phase of a quantum dot via interferometry can reveal the symmetry of the orbitals and details of electron transport. Crucially, interferometry will enable the read-out of topological qubits based on one-dimensional nanowires. However, measuring the transmission phase of a quantum dot in a nanowire has not yet been established. Here, we exploit recent breakthroughs in the growth of one-dimensional networks and demonstrate interferometric read-out in a nanowire-based architecture. In our two-path interferometer, we define a quantum dot in one branch and use the other path as a reference arm. We observe Fano resonances stemming from the interference between electrons that travel through the reference arm and undergo resonant tunnelling in the quantum dot. Between consecutive Fano peaks, the transmission phase exhibits phase lapses that are affected by the presence of multiple trajectories in the interferometer. These results provide critical insights for the design of future topological qubits.
通过干涉测量法检测量子点的传输相位可以揭示轨道的对称性和电子输运的细节。至关重要的是，干涉测量法将能够读出基于一维纳米线的拓扑量子比特。然而，测量纳米线中量子点的传输相位尚未实现。在这里，我们利用一维网络生长方面的最新突破，并展示了基于纳米线架构的干涉测量读出。在我们的双路径干涉仪中，我们在一个分支中定义一个量子点，并将另一条路径用作参考臂。我们观察到法诺共振，其源于通过参考臂传播并在量子点中经历共振隧穿的电子之间的干涉。在连续的法诺峰之间，传输相位呈现出相位突变，这些突变受到干涉仪中多条轨迹的影响。这些结果为未来拓扑量子比特的设计提供了关键见解。
