  In the quest for quantum spin liquids, thin films are expected to open the
way for the control of intricate magnetic interactions in actual materials by
exploiting epitaxial strain and two-dimensionality. However, materials
compatible with conventional thin-film growth methods have largely remained
undeveloped. As a promising candidate towards the materialization of quantum
spin liquids in thin films, we here present a robust ilmenite-type oxide with a
honeycomb lattice of edge-sharing IrO$_6$ octahedra artificially stabilized by
superlattice formation with an ilmenite-type antiferromagnetic oxide MnTiO$_3$.
The stabilized sub-unit-cell-thick Mn-Ir-O layer is isostructural to MnTiO$_3$,
having the atomic arrangement corresponding to ilmenite-type MnTiO$_3$ not
discovered yet. By spin Hall magnetoresistance measurements, we found that
antiferromagnetic ordering in the ilmenite Mn sublattice is suppressed by
modified magnetic interactions in the MnO$_6$ planes via the IrO$_6$ planes.
These findings lay the foundation for the creation of two-dimensional Kitaev
candidate materials, accelerating the discovery of exotic physics and
applications specific to quantum spin liquids.
