Abstract
Multi-Weyl semimetals are new types of topological semimetals whose topological charge is equal to the value of the winding number . Here, we investigate the single-particle ballistic scattering on a rectangular barrier in multi-Weyl semimetals. Because this system has a crystallographic anisotropy, the scattering properties depend on the mutual orientation of the crystalline axis and the barrier. For different , the vertical component of the wave vector and the corresponding probability current density satisfies . In the case of a barrier perpendicular to the -axis, it is found that the reflectionless incident angles are determined by geometrical resonances between the barrier width and the de Broglie length of the scattered electrons in the barrier region. In the -axis direction, the local minimum conductance occurs when the chemical potential equals the barrier height and , where is the width of the barrier. Differently, in the case of a barrier perpendicular to the -axis, the angular distribution of the transmission probability is no longer rotation invariant. For the double-Weyl semimetals (), the transmission probability decreases rapidly to 0 as the barrier width increases for a normal incidence, which is similar to conventional nonrelativistic electrons. It is interesting that perfect transmission is again found for normally incident Weyl fermions for the triple-Weyl semimetals (). In this case, the tunneling indicates a property similar to that in the case of .
4 More- Received 28 July 2019
- Accepted 22 January 2020
DOI:https://doi.org/10.1103/PhysRevB.101.085410
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