Selective-Area-Grown PbTe-Pb Planar Josephson Junctions for Quantum Devices
Ruidong Li, Wenyu Song, Wentao Miao, Zehao Yu, Zhaoyu Wang, Shuai Yang, Yichun Gao, Yuhao Wang, Fangting Chen, Zuhan Geng, Lining Yang, Jiaye Xu, Xiao Feng, Tiantian Wang, Yunyi Zang, Lin Li, Runan Shang, Qi‐Kun Xue, Ke He, Hao Zhang
Abstract
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 superconductor Pb. Scanning transmission electron microscopy reveals a sharp semiconductor-superconductor interface. Gate-tunable supercurrents 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.