Supercurrent through single electron transverse mode in 1D Josephson junctions QPC

We study Josephson Junctions (JJs) in InSb nanowires with 15nm Tin shells [1]. We observe quantized conductance plateaus. This phenomenon is the evidence of transparent transmission and ballistic transport, which is known as Quantum Point Contacts (QPC). In the gate voltage range where conductance is corresponding to the 1^st electron sub-band, we obtain supercurrent carried by single transverse mode. We study gate voltage and magnetic field dependence of supercurrent in the 1^st electron mode. In a previous paper, it has been demonstrated that supercurrent in an external parallel field is affected by the interference between transverse modes. In the contrast, a numerical simulation based on the tight-binding model predicts that the supercurrent carried by the single mode is less affected by the interference [2]. Our measurement results have good agreement with this theoretical prediction.



[1]. M. Pendharkar., et al., Science 372, 508(2021)

[2]. K. Zuo et al., PRL., 119, 187704(2017)