Potts Heidi, Aspegren Markus, Debbarma Rousan, Lehmann Sebastian, Thelander Claes
Division of Solid State Physics and NanoLund, Lund University, SE-221 00 Lund, Sweden.
Nanotechnology. 2023 Jan 20;34(13). doi: 10.1088/1361-6528/aca90e.
We have performed tunnel transport spectroscopy on a quantum dot (QD) molecule proximitized by a superconducting contact. In such a system, the scattering between QD spins and Bogoliubov quasiparticles leads to the formation of Yu-Shiba-Rusinov (YSR) states within the superconducting gap. In this work, we investigate interactions appearing when one- and two-electron spin states in a double-QD energetically align with the superconducting gap edge. We find that the inter-dot spin-triplet state interacts considerably stronger with the superconductor than the corresponding singlet, pointing to stronger screening. By forming a ring molecule with a significant orbital contribution to the effective-factor, we observe interactions of all four spin-orbital one-electron states with the superconductor under a weak magnetic field.
我们对由超导接触近邻化的量子点(QD)分子进行了隧穿输运光谱研究。在这样的系统中,量子点自旋与博戈留波夫准粒子之间的散射导致在超导能隙内形成汤川-志波-鲁西诺夫(YSR)态。在这项工作中,我们研究了双量子点中一个和两个电子自旋态在能量上与超导能隙边缘对齐时出现的相互作用。我们发现,点间自旋三重态与超导体的相互作用比相应的单重态强得多,这表明屏蔽作用更强。通过形成对有效因子有显著轨道贡献的环状分子,我们在弱磁场下观察到了所有四个自旋-轨道单电子态与超导体的相互作用。