Authors: Shixian Chen, Wanghao Tian, Zuyu Xu, Ping Zhang, Hongmei Du, Zihan Wei, Dingding Li, Yangyang Lv, Hancong Sun, Yong-Lei Wang, Dieter Koelle, Reinhold Kleiner, Huabing Wang and Peiheng Wu
Physical Review B 104, 214512 (2021)
Abstract: van der Waals Josephson junctions utilize the interface between two superconducting NbSe2 crystal flakes as a tunnel barrier. We fabricate such junctions by a dry-transfer procedure and characterize them by electric transport experiments at various temperatures and under microwave irradiation at frequencies up to 224 GHz. We observe integer Shapiro steps in the current-voltage characteristics indicating a sinusoidal Josephson current-phase relation and the possibility to use this kind of junction even in the terahertz frequency range.