We report transport measurements on Josephson junctions consisting of Bi2Te3 topological insulator (TI) thin films contacted by superconducting Nb electrodes. For a device with junction length L = 134 nm, the critical supercurrent Ic can be modulated by an electrical gate which tunes the carrier type and density of the TI film. Ic can reach a minimum when the TI is near the charge neutrality regime with the Fermi energy lying close to the Dirac point of the surface state. In the p-type regime the Josephson current can be well described by a short ballistic junction model. In the n-type regime the junction is ballistic at 0.7 K < T < 3.8 K while for T < 0.7 K the diffusive bulk modes emerge and contribute a larger Ic than the ballistic model. We attribute the lack of diffusive bulk modes in the p-type regime to the formation of p-n junctions. Our work provides new clues for search of Majorana zero mode in TI-based superconducting devices.
@article{arxiv.2103.05215,
title = {Gate Tunable Supercurrent in Josephson Junctions Based on Bi2Te3 Topological Insulator Thin Films},
author = {Wei-Xiong Wu and Yang Feng and Yun-He Bai and Yu-Ying Jiang and Zong-Wei Gao and Yuan-Zhao Li and Jian-Li Luan and Heng-An Zhou and Wan-Jun Jiang and Xiao Feng and Jin-Song Zhang and Hao Zhang and Ke He and Xu-Cun Ma and Qi-Kun Xue and Ya-Yu Wang},
journal= {arXiv preprint arXiv:2103.05215},
year = {2021}
}
Comments
6 pages, 4 figures, The manuscript with the same title will be published by Chinese Physics Letters