  We investigate the confined states and transport of three-dimensional Weyl
electrons around a one-dimensional external rectangular electrostatic
potential. Confined states with finite transverse wave vector exist at energies
higher than the half well depth or lower than the half barrier height. The
rectangular potential appears completely transparent to normal incident
electrons but not otherwise. The tunneling transmission coefficient is
sensitive to their incident angle and shows resonant peaks when their energy
coincides with the confined spectra. In addition, for electrons in the
conduction (valence) band through a potential barrier (well), the transmission
spectrum has a gap of width increasing with the incident angle. Interestingly,
the electron linear zero-temperature conductance over the potential can
approach zero when the Fermi energy is aligned to the top and bottom energies
of the potential, when only electron beams normal to the potential interfaces
can pass through. The considered structure can be used to collimate Weyl
electron beams.
