Electronic and Magnetic Structure under Lattice Distortion in SrIrO 3 /SrTiO 3 Superlattice: A First-Principles Study

作者：Wei Fan, Seiji Yunoki · 发表于：Journal of Physics Conference Series · 年份：2015 · DOI：10.1088/1742-6596/592/1/012139 · 被引用次数：15 · 研究领域：Advanced Condensed Matter Physics、Magnetic and transport properties of perovskites and related materials、Multiferroics and related materials

Motivated by recent experiments on (001) [SrIrO 3 ] m /[SrTiO 3 ] 1 superlattice (J. Matsuno, et al., arXiv:1401.1066 ), we perform first-principles calculations to study the electronic and magnetic structure of this superlattice under lattice distortion. We consider two different magnetic structures, a non-collinear in-plane canted antiferromagnetic (AFM) order and a collinear AFM order along c direction, and find that these two AFM states exhibit different strain dependence. The canted AFM order is enhanced with compressive strain while the collinear AFM order is enhanced with tensile strain. Moreover, the local magnetic moments of these magnetic structures show different linear dependence with respect to compressive or tensile epitaxial strain. We also find that the electronic band structure is sensitive to strain, local rotation, and ab -plane Ir-O bond length. Under a certain condition of lattice distortion, the band gap is even closed to induce an effective total angular momentum J eff = 1/2 metal. These unexpected behaviors deserve more careful investigation on the microscopic mechanism played by a strong spin-orbit coupling, electron correlations, and lattice distortion.