The three-dimensional topological Dirac semimetal, as a new type of topological materials, has attracted great attention in condensed matter physics. There, the conduction and valence band touch only at discrete points and disperse linearly along all (three) momentum directions—a natural 3D counterpart of graphene, as well as a gapless topological insulator.

Prof. Jian Wang at PKU, in collaboration with Prof. Xincheng Xie at PKU (theory), Prof. Shuang Jia at PKU (single crystal sample growth), Prof. Junfeng Wang at WNHMFC (Pulsed high magnetic field measurement), Prof. Yong Wang at ZJU (TEM measurements), as well as Prof. Zhili Xiao at the Argonne National Laboratory (single crystal XRD measurement) made new achievement in the magnetotransport in Cd3As2 single crystal to show the complete three dimensional Fermi surface. From the SdH analysis in different magnetic field direction, it is found when the magnetic field lies in [112] and [44-1] axis, only single oscillation period features present, however, the system shows double period oscillations when the field is applied along [1-10] direction. Moreover, combined with angular dependence of SdH oscillations at different magnetic field directions, they illustrate a complete 3D Fermi surfaces with two nested anisotropic ellipsoids around the Dirac points. Furthermore, by measuring the magnetoresistance up to 60 T, the quantum limit (n = 1 Landau level) at about 43 T is observed. In addition, ultrahigh mobility up to the scale of 10 million cm2/Vs is detected. The results were published in Physical Review X (PRX 5, 031037(2015)). Jian Wang, X.C. Xie and Shuang Jia at PKU are corresponding authors of this paper. Yanfei Zhao and Haiwen Liu at PKU contributed equally to this work.

The work was supported by National Basic Research Programs of China, National Natural Science Foundation of China, 1000 Talents Program for Young Scientists of China, the Research Fund for the Doctoral Program of Higher Education (RFDP) of China, and Collaborative Innovation Center of Quantum Matter, China.