Van der Waals (vdW) Josephson junctions can possibly accelerate the development of advanced superconducting device that utilizes the unique properties of two-dimensional (2D) transition metal dichalcogenide (TMD) superconductors such as spin-orbit coupling, spin-valley locking. Here, we fabricate vertically stacked NbS2/NbS2 Josephson junctions using a modified all-dry transfer technique and characterize the device performance via systematic low-temperature transport measurements. The experimental results show that the superconducting transition temperature of the NbS2/NbS2 Josephson junction is 5.84 K, and the critical current density reaches 3975 A/cm2 at 2K. Moreover, we extract a superconducting energy gap Δ=0.58 meV, which is considerably smaller than that expected from the single band s-wave Bardeen-Cooper-Schrieffer (BCS) model (Δ=0.89 meV).
@article{arxiv.2211.01609,
title = {Josephson Effect in NbS$_{2}$ van der Waals Junctions},
author = {Chuanwen Zhao and Xin Yi and Qiao Chen and Chengyu Yan and Shun Wang},
journal= {arXiv preprint arXiv:2211.01609},
year = {2022}
}