2016/09/19 by Shumeng Chi, Zheng Li, Zhilin Li +5
Materials Science · Physics and Astronomy · #Anisotropy #Band gap #Condensed matter physics #Fermion #Geometry #Graphene research and applications #Physics #Quantum Mechanics and Non-Hermitian Physics #Quantum mechanics #Semimetal #Surface (topology) #Surface states #Symmetry (geometry) #Topological Materials and Phenomena #Topology (electrical circuits) #Weyl semimetal #cond-mat.mtrl-sci
paper · pdf · doi:10.1002/andp.201600359
arxiv created 2016/09/19 · openalex publication_date 2017/02/13 · arxiv updated 2017/04/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
A Weyl semimetal (WSM) features Weyl fermions in its bulk and topological surface states on surfaces, and is novel material hosting Weyl fermions, a kind of fundamental particles. The WSM was regarded as a three‐dimensional version of “graphene” under the illusion. In order to explore its promising photoelectric properties and applications in photonics and photoelectronics, here, we study the anisotropic linear and nonlinear optical responses of a WSM TaAs, which are determined by the relationship and balance between its topological surface states and Weyl nodes. We demonstrate that topological surface states which break the bulk symmetry are responsible for the anisotropy of the mobility, and the anisotropic nonlinear response shows saturable characteristic with extremely large saturable intensity. We also find that the mobility is anisotropic with the magnitude of 10 4 cm 2 V −1 s −1 at room temperature and can be accelerated by the optical field. By analyzing the symmetry, the nonlinear response is mainly contributed by the fermions close to the Weyl nodes, and is related to the Pauli's blocking of fermions, electron‐electron interaction. This work experimentally discovers the anisotropic ultrahigh mobility of WSMs in the optical field and may start the field for the applications of WSMs in photonics and photoelectronics. image