Sunday, June 29, 2014
A pair of Weyl fermions protected by crystalline symmetry has been proposed to appear as low-energy excitations in a number of materials termed 3D Dirac semimetals. Cd3As2 known to have a high mobility is one of the first candidates to exhibit a bulk 3D Dirac semimetal phase which is protected by the C4 symmetry of the crystalline structure. In recent study, our group has revealed the novel band structure of the Cd3As2 by combining the Landau level spectroscopy and the quasiparticle interference. Our measurements show a remarkable linear dispersion in wide energy range which extended the understanding of ultra-high mobility nature of Cd3As2. In addition to that simulating the model Hamiltonian with parameters which reproduce the experimental data suggests Weyl fermions are the low-energy excitations when a magnetic field applied along the axis of the Dirac points.
Published in Nature Materials:
Landau Quantization and Quasiparticle Interference in the Three-Dimensional Dirac Semimetal Cd3As2, Sangjun Jeon, Brian B. Zhou, Andras Gyenis, Benjamin E. Feldman, Itamar Kimchi, Andrew C. Potter, Quinn D. Gibson, Robert J. Cava, Ashvin Vishwanath, Ali Yazdani, Nature Materials 13, 851-856 (2014). (Letter)