Structural distortion-induced magnetoelastic locking in sr2iro4 revealed through nonlinear optical harmonic generation

D. H. Torchinsky, H. Chu, L. Zhao, N. B. Perkins, Y. Sizyuk, T. Qi, G. Cao, D. Hsieh

Research output: Contribution to journalArticlepeer-review

50 Scopus citations

Abstract

We report a global structural distortion in Sr2IrO4 using spatially resolved optical second and third harmonic generation rotational anisotropy measurements. A symmetry lowering from an I41/acd to I41/a space group is observed both above and below the Néel temperature that arises from a staggered tetragonal distortion of the oxygen octahedra. By studying an effective superexchange Hamiltonian that accounts for this lowered symmetry, we find that perfect locking between the octahedral rotation and magnetic moment canting angles can persist even in the presence of large noncubic local distortions. Our results explain the origin of the forbidden Bragg peaks recently observed in neutron diffraction experiments and reconcile the observations of strong tetragonal distortion and perfect magnetoelastic locking in Sr2IrO4.

Original languageEnglish (US)
Article number096404
JournalPhysical review letters
Volume114
Issue number9
DOIs
StatePublished - Mar 5 2015

Bibliographical note

Publisher Copyright:
© 2015 American Physical Society.

Fingerprint

Dive into the research topics of 'Structural distortion-induced magnetoelastic locking in sr2iro4 revealed through nonlinear optical harmonic generation'. Together they form a unique fingerprint.

Cite this