  Epitaxial heterostructures composed of complex oxides have fascinated
researchers for over a decade as they offer multiple degrees of freedom to
unveil emergent many-body phenomena often unattainable in bulk. Recently, apart
from stabilizing such artificial structures along the conventional
[001]-direction, tuning the growth direction along unconventional
crystallographic axes has been highlighted as a promising route to realize
novel quantum many-body phases. Here we illustrate this rapidly developing
field of geometrical lattice engineering with the emphasis on a few
prototypical examples of the recent experimental efforts to design complex
oxide heterostructures along the (111) orientation for quantum phase discovery
and potential applications.
