Unidirectional spin density wave state in metallic (SrLa )IrO.

Materials that exhibit both strong spin-orbit coupling and electron correlation effects are predicted to host numerous new electronic states. One prominent example is the J = 1/2 Mott state in SrIrO, where introducing carriers is predicted to manifest high temperature superconductivity analogous to the S = 1/2 Mott state of LaCuO. While bulk superconductivity currently remains elusive, anomalous quasiparticle behaviors paralleling those in the cuprates such as pseudogap formation and the formation of a d-wave gap are observed upon electron-doping SrIrO. Here we establish a magnetic parallel between electron-doped SrIrO and hole-doped LaCuO by unveiling a spin density wave state in electron-doped SrIrO. Our magnetic resonant X-ray scattering data reveal the presence of an incommensurate magnetic state reminiscent of the diagonal spin density wave state observed in the monolayer cuprate (LaSr )CuO. This link supports the conjecture that the quenched Mott phases in electron-doped SrIrO and hole-doped LaCuO support common competing electronic phases.