Electronic and Magnetic Structure under Lattice Distortion in SrIrO3/SrTiO3 Superlattice: A First-Principles Study

International Conference on Strongly Correlated Electron Systems 2014

Fan, Wei^1 ; Yunoki, Seiji^1,2,3

Computational Condensed Matter Physics Laboratory, RIKEN, Wako, Saitama

351-0198, Japan^1

Computational Quantum Matter Research Team, RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama

351-0198, Japan^2

Computational Materials Science Research Team, RIKEN Advanced Institute for Computational Science (AICS), Hyogo, Kobe

650-0047, Japan^3

关键词: Antiferromagnetic orders;    Electronic band structure;    First-principles calculation;    First-principles study;    Lattice distortions;    Local magnetic moments;    Microscopic mechanisms;    Spin-orbit couplings;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/592/1/012139/pdf
DOI  :  10.1088/1742-6596/592/1/012139

来源: IOP

【 摘 要 】

Motivated by recent experiments on (001) [SrIrO3]m/[SrTiO3]1superlattice (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 Jeff1/2 metal. These unexpected behaviors deserve more careful investigation on the microscopic mechanism played by a strong spin-orbit coupling, electron correlations, and lattice distortion.