Planar Josephson junctions are predicted to host Majorana zero modes. The material platforms in previous studies are two dimensional electron gases (InAs, InSb, InAsSb and HgTe) coupled to a superconductor such as Al or Nb. Here, we introduce a new material platform for planar JJs, the PbTe-Pb hybrid. The semiconductor, PbTe, was grown as a thin film via selective area epitaxy. The Josephson junction was defined by a shadow wall during the deposition of the superconductor Pb. Scanning transmission electron microscopy reveals a sharp semiconductor-superconductor interface. Gate-tunable supercurrent and multiple Andreev reflections are observed. A perpendicular magnetic field causes interference patterns of the switching current, exhibiting Fraunhofer-like and SQUID-like behaviors. We further demonstrate a prototype device for Majorana detection, wherein phase bias and tunneling spectroscopy are applicable.
@article{arxiv.2311.16815,
title = {Selective-Area-Grown PbTe-Pb Planar Josephson Junctions for Quantum Devices},
author = {Ruidong Li and Wenyu Song and Wentao Miao and Zehao Yu and Zhaoyu Wang and Shuai Yang and Yichun Gao and Yuhao Wang and Fangting Chen and Zuhan Geng and Lining Yang and Jiaye Xu and Xiao Feng and Tiantian Wang and Yunyi Zang and Lin Li and Runan Shang and Qi-Kun Xue and Ke He and Hao Zhang},
journal= {arXiv preprint arXiv:2311.16815},
year = {2024}
}