Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark.
Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia.
Phys Rev Lett. 2018 Dec 21;121(25):257701. doi: 10.1103/PhysRevLett.121.257701.
We demonstrate the Josephson effect in a serial double quantum dot defined in a nanowire with epitaxial superconducting leads. The supercurrent stability diagram adopts a honeycomb pattern. We observe sharp discontinuities in the magnitude of the critical current, I_{c}, as a function of dot occupation, related to doublet to singlet ground state transitions. Detuning of the energy levels offers a tuning knob for I_{c}, which attains a maximum at zero detuning. The consistency between experiment and theory indicates that our device is a faithful realization of the two-impurity Anderson model.
我们在纳米线中定义的串联双量子点中展示了约瑟夫森效应，该量子点具有外延超导引线。超导电流稳定图呈蜂窝状图案。我们观察到临界电流 Ic 的大小作为点占据的函数出现急剧不连续，这与双重到单重基态跃迁有关。能级失谐为 Ic 提供了一个调谐旋钮，在零失谐时达到最大值。实验和理论之间的一致性表明，我们的器件是双杂质安德森模型的忠实实现。
