Metal-insulator transition of (SrIrO3)1/(NdNiO3)3 superlattice under strain

We investigate the magnetic and electronic properties of strongly correlated perovskite ${({\mathrm{SrIrO}}_{3})}_{1}/{({\mathrm{NdNiO}}_{3})}_{3}$ superlattice by density-functional theory calculations. The semiconducting ground state of the superlattice adopts a metal-insulator transition (MIT) under compressive epitaxial strain. This MIT is induced by the large reduction of breathing distortion and octahedra antiferrodistortive distortion in the superlattice compared to the ${\mathrm{NdNiO}}_{3}$ under epitaxial strain. Furthermore, it is found that this breathing distortion couples to the T-type antiferromagnetic ordering with two types of magnetic order on Ni sublattices, leading to a magnetic state without the degenerate switched magnetic direction when the breathing distortion is unchanged. Our results provide a mechanism of MIT in superlattice and a possible way to tune the magnetic order by breathing distortion.