  It is proposed that strain-induced pseudomagnetic fields in Dirac and Weyl
materials could be used as valley and chirality sensitive lenses for beams of
Weyl quasiparticles. The study of the (pseudo-)magnetic lenses is performed by
using the eikonal approximation for describing the Weyl quasiparticles
propagation in magnetic and strain-induced pseudomagnetic fields. Analytical
expressions for the locations of the principal foci and the focal lengths are
obtained in the paraxial approximation in the models with uniform as well as
nonuniform effective magnetic fields inside the lens. The results show that the
left- and right-handed quasiparticles can be focused at different spatial
locations when both magnetic and pseudomagnetic fields are applied. It is
suggested that the use of magnetic and pseudomagnetic lenses could open new
ways of producing and manipulating beams of chiral Weyl quasiparticles.
