  Chiral magnets are materials which possess unique helical arrangements of
magnetic moments, which give rise to nonreciprocal transport and fascinating
physics phenomena. On the one hand, their exploration is guided by the
prospects of unconventional signal processing, computation schemes and magnetic
memory. On the other hand, progress in applications is hindered by the
challenging materials synthesis, limited scalability and typically low critical
temperature. Here, we report the creation and exploration of artificial chiral
magnets (ACMs) at room temperature. By employing a mass production compatible
deposition technology, we synthesize ACMs, which consist of helical Ni surfaces
on central cylinders. Using optical microscopy, we reveal nonreciprocal magnon
transport at GHz frequencies. It is controlled by programmable toroidal moments
which result from the ACM's geometrical handedness and field-dependent spin
chirality. We present materials-by-design rules which optimize the helically
curved ferromagnets for 3D nonreciprocal transport at room temperature and zero
magnetic field.
