Anisotropic magnetic couplings and structure-driven canted to collinear transitions in Sr2IrO4 by magnetically constrained noncollinear DFT

Autor(en)

Peitao Liu, Sergii Khmelevskyi, Bongjae Kim, Martijn Marsman, Dianzhong Li, Xing-Qiu Chen, D. D. Sarma, Georg Kresse, Cesare Franchini

Abstrakt

We study the canted magnetic state in Sr2IrO4 using fully relativistic density functional theory (DFT) including an on-site Hubbard U correction. A complete magnetic phase diagram with respect to the tetragonal distortion and the rotation of IrO6 octahedra is constructed, revealing the presence of two types of canted to collinear magnetic transitions: a spin-flop transition with increasing tetragonal distortion and a complete quenching of the basal weak ferromagnetic moment below a critical octahedral rotation. Moreover, we put forward a scheme to study the anisotropic magnetic couplings by mapping magnetically constrained noncollinear DFT onto a general spin Hamiltonian. This procedure allows for the simultaneous account and direct control of the lattice, spin, and orbital interactions within a fully ab initio scheme. We compute the isotropic, single site anisotropy and Dzyaloshinskii-Moriya (DM) coupling parameters, and clarify that the origin of the canted magnetic state in Sr2IrO4 arises from the structural distortions and the competition between isotropic exchange and DM interactions.

Organisation(en)

Computergestützte Materialphysik

Externe Organisation(en)

Chinese Academy of Sciences (CAS), Indian Institute of Science, Budapest University of Technology and Economics

Journal

Physical Review B

Band

92

Anzahl der Seiten

6

ISSN

1098-0121

DOI

https://doi.org/10.1103/PhysRevB.92.054428

Publikationsdatum

08-2015

Peer-reviewed

Ja

ÖFOS 2012

103025 Quantenmechanik, 103036 Theoretische Physik, 103015 Kondensierte Materie, 103009 Festkörperphysik

ASJC Scopus Sachgebiete

Electronic, Optical and Magnetic Materials, Condensed Matter Physics

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/9b1ad3ae-b5de-49d0-835b-58cb80d8199a