  Low-dimensional quantum magnetism presents a seemingly unlimited source of
rich, intriguing physics. Yet, as realistic experimental representations are
hard to come by, the field remains predominantly theoretical. In recent years,
artificial spin structures built through manipulation of magnetic atoms in a
scanning tunnelling microscope have developed into a promising testing ground
for experimental verification of theoretical models. Here we present an
overview of available tools and discuss recent achievements as well as future
avenues. Moreover, we show new observations on magnetic switching in a bistable
bit that can be used to extrapolate information on the magnetisation of the
microscope tip.
