摘要
We report transport measurements on Josephson junctions consisting of Bi_(2)Te_(3) 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.
作者
Wei-Xiong Wu
Yang Feng
Yun-He Bai
Yu-Ying Jiang
Zong-Wei Gao
Yuan-Zhao Li
Jian-Li Luan
Heng-An Zhou
Wan-Jun Jiang
Xiao Feng
Jin-Song Zhang
Hao Zhang
Ke He
Xu-Cun Ma
Qi-Kun Xue
Ya-Yu Wang
吴伟雄;冯洋;白云鹤;姜钰莹;高宗伟;李远昭;栾建立;周恒安;江万军;冯硝;张金松;张浩;何珂;马旭村;薛其坤;王亚愚(State Key Laboratory of Low Dimensional Quantum Physics,Department of Physics,Tsinghua University,Beijing 100084,China;State Key Laboratory of Surface Physics and Department of Physics,Fudan University,Shanghai 200438,China;Frontier Science Center for Quantum Information,Beijing 100084,China;Beijing Academy for Quantum Information Sciences,Beijing 100084,China)
基金
Supported by the Basic Science Center Project of the National Natural Science Foundation of China(Grant No.51788104)
the National Key R&D Program of China(Grant No.2017YFA0302900)。
