  The investigation of curved low-dimensional systems is a topic of great
research interest. Such investigations include two-dimensional systems with
cylindrical symmetry. In this work, we present a numerical study of the
electronic transport properties of metallic nanotubes deviating from the
cylindrical form either by having a bump or a depression, and under the
influence of a magnetic field. Under these circumstances, it is found that the
nanotube may be used as an energy high-pass filter for electrons. It is also
shown that the device can be used to tune the angular momentum of transmitted
electrons.
