Research

PKU research group makes progress in High Mobility Three-Dimensional Dirac Semimetal Cd3As2

SEP . 25 2015
Peking University, Sep. 25, 2015: 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. Wang Jian at PKU, in collaboration with Prof. Xie Xincheng at PKU (theory), Prof. Jia Shuang at PKU (single crystal sample growth), Prof. Wang Junfeng at WNHMFC (Pulsed high magnetic field measurement), Prof. Wang Yong at ZJU (TEM measurements), as well as Prof. Xiao Zhili at the Argonne National Laboratory (single crystal XRD measurement) made achievement in the magneto transport 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 magneto resistance up to60 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/Vsis detected. The results were published in Physical Review X (PRX5, 031037(2015)). Wang Jian, Xie X.C. and Jia Shuang at PKU are corresponding authors of this paper. Zhao Yanfei and Liu Haiwen at PKU contributed equally to this work.
 
The work was supported by National Basic Research Programs of China, National Natural Science Foundation of China, the Thousand 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.


 
Figure: Experiments and analysis show the sophisticated geometry of Fermi surface with two nested anisotropic ellipsoids around the Dirac points and quantum linear magneto resistance above 43 Tesla as well as the Zeeman splitting in high mobility Cd3As2 crystals (3D Topological Dirac semimetal) at low temperatures and high magnetic fields (up to 60 Tesla).

Source: International Center for Quantum Materials

Edited by: Zhang Jiang