Abstract
Recently, it has been theoretically predicted that Cd3As2 is a three dimensional Dirac material, a new topological phase discovered after topological insulators, which exhibits a linear energy dispersion in the bulk with massless Dirac fermions. Here, we report on the low-temperature magnetoresistance measurements on a ~50 nm-thick Cd3As2 film. The weak antilocalization under perpendicular magnetic field is discussed based on the two-dimensional Hikami-Larkin-Nagaoka (HLN) theory. The electron-electron interaction is addressed as the source of the dephasing based on the temperature-dependent scaling behavior. The weak antilocalization can be also observed while the magnetic field is parallel to the electric field due to the strong interaction between the different conductance channels in this quasi-two-dimensional film.
Highlights
It has been theoretically predicted that Cd3As2 is a three dimensional Dirac material, a new topological phase discovered after topological insulators, which exhibits a linear energy dispersion in the bulk with massless Dirac fermions
Theory predicts that Cd3As2 3 and Na3Bi4 are the three dimensional (3D) Dirac materials, soon after which, they have been experimentally demonstrated by angle-resolved photoemission spectroscopy (ARPES)[5,6,7], scanning tunneling microscope (STM)[8] and electrical transport measurements[9]
Various novel topological phases, such as Weyl semimetals, topological insulators and topological superconductors can be obtained from 3D Dirac materials by breaking the time reversal symmetry or inversion symmetry[10,11]
Summary
It has been theoretically predicted that Cd3As2 is a three dimensional Dirac material, a new topological phase discovered after topological insulators, which exhibits a linear energy dispersion in the bulk with massless Dirac fermions. The weak antilocalization can be observed while the magnetic field is parallel to the electric field due to the strong interaction between the different conductance channels in this quasitwo-dimensional film. WAL phenomenon is always observed in Dirac materials, such as topological insulators and graphene without inter-valley scattering, as an important consequence of spin-momentum locking and the full suppression of backscattering, resulting in a relative π Berry phase acquired by electrons executing time-reversed paths[26,27]. The WAL effect by theoretical description using the Feynman diagram shows its origin from the inter-valley scattering as described in two-dimensional (2D) Dirac materials such as graphene and topological insulators[30]. As an effective tool to investigate the scattering ratio in parallel www.nature.com/scientificreports/
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