September 20, 2011 | A.A. Burkov1,2 and Leon Balents2
The authors propose a simple realization of the three-dimensional (3D) Weyl semimetal phase using a multilayer structure composed of identical thin films of a magnetically-doped 3D topological insulator (TI) separated by ordinary-insulator spacer layers. They show that this system contains a Weyl semimetal phase with only two Dirac nodes of opposite chirality, separated in momentum space, in its band structure. This Weyl semimetal exhibits finite anomalous Hall conductivity, chiral edge states, and is an intermediate phase between an ordinary insulator and a 3D quantum anomalous Hall insulator. The Weyl semimetal has a nonzero DC conductivity at zero temperature but a Drude weight that vanishes as \( T^2 \), making it an unusual metallic phase. The authors also discuss the topologically protected edge states and the influence of disorder on the transport properties of the Weyl semimetal.The authors propose a simple realization of the three-dimensional (3D) Weyl semimetal phase using a multilayer structure composed of identical thin films of a magnetically-doped 3D topological insulator (TI) separated by ordinary-insulator spacer layers. They show that this system contains a Weyl semimetal phase with only two Dirac nodes of opposite chirality, separated in momentum space, in its band structure. This Weyl semimetal exhibits finite anomalous Hall conductivity, chiral edge states, and is an intermediate phase between an ordinary insulator and a 3D quantum anomalous Hall insulator. The Weyl semimetal has a nonzero DC conductivity at zero temperature but a Drude weight that vanishes as \( T^2 \), making it an unusual metallic phase. The authors also discuss the topologically protected edge states and the influence of disorder on the transport properties of the Weyl semimetal.