Large transverse current in topological Dirac semimetal Cd3As2
Wei-Li Lee1*, Shih-Ting Guo1, R. Sankar1, Yung-Yu Chien1, Tay-Rong Chang4, Horng-Tay Jeng4, Guang-Yu Guo3, F.C. Chou2
1物理研究所, 中央研究院, 台北, Taiwan
2凝態科學中心, 台灣大學, 台北, Taiwan
3物理系, 台灣大學, 台北, Taiwan
4物理系, 清華大學, 新竹, Taiwan
* presenting author:Wei-Li Lee,
Cadmium arsenide (Cd3As2) is known for its inverted band structure and ultra-high electron mobility. It has been theoretically predicted and also confirmed by ARPES experiments to exhibit a 3D Dirac semimetal phase containing degenerate Weyl nodes. From magneto-transport measurements in high quality single crystals of Cd3As2, a small effective mass m∗ ≈ 0.05 me is determined from the Shubnikov-de Haas (SdH) oscillations. In certain field orientations, we find a splitting of the SdH oscillation frequency in the FFT spectrum suggesting a possible lifting of the double degeneracy in accord with the helical spin texture at outer and inner Fermi surfaces with opposite chirality predicted by our ab initio calculations. Strikingly, a large antisymmetric magnetoresistance with respect to the applied magnetic fields is uncovered over a wide temperature range in needle crystal of Cd3As2 with its long axis along [112] crystal direction. It reveals a significant contribution of intrinsic anomalous velocity term in the transport equation intimately related to the unique 3D Rashba-like spin splitted bands in defected Cd3As2.

Keywords: Dirac semimetal, Topological materials, Rashba spin-splitting, Weyl semimetal