  We establish theoretically that in nonmagnetic semiconducting bilayer or
multilayer thin film systems rolled up into compact quasi-one-dimensional
nanoarchitectures, the ballistic magnetoresistance is very anisotropic:
conductances depend strongly on the direction of an externally applied magnetic
field. This phenomenon originates from the curved open geometry of rolled-up
nanotubes, which leads to a tunability of the number of quasi-one-dimensional
magnetic subbands crossing the Fermi energy. The experimental significance of
this phenomenon is illustrated by a sizable anisotropy that scales with the
inverse of the winding number, and persists up to a critical temperature that
can be strongly enhanced by increasing the strength of the external magnetic
field or the characteristic radius of curvature, and can reach room
temperature.
