CaltechAUTHORS
Published March 6, 2015 | Version Submitted + Published
Journal Article Open

Structural Distortion-Induced Magnetoelastic Locking in Sr_2IrO_4 Revealed through Nonlinear Optical Harmonic Generation

Creators

  • 1. ROR icon California Institute of Technology
  • 2. ROR icon University of Minnesota
  • 3. ROR icon University of Kentucky

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 I4_1/acd to I4_1/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 Sr_2IrO_4.

Additional Information

© 2015 American Physical Society. Received 10 July 2014; published 5 March 2015. We acknowledge useful discussions with Feng Ye, Bryan Chakoumakos, Stephen Lovesey, Dmitry Khalyavin, Peter Woelfle and Stephen Wilson. D. H. acknowledges support by the U.S. Army Research Office under Grant No. W911NF-13-1-0059. Instrumentation for the NHG-RA setup was partially supported by a U.S. Army Research Office DURIP Award under Grant No. W911NF-13-1-0293. D. H. acknowledges funding provided by the Institute for Quantum Information and Matter, an NSF Physics Frontiers Center (PHY-1125565) with support of the Gordon and Betty Moore Foundation through Grant No. GBMF1250. N. P. and Y. S. acknowledge NSF support via Grants No. DMR-1255544 and No. DMR-1005932. G. C. acknowledges NSF support via Grant No. DMR-1265162.

Attached Files

Published - PhysRevLett.114.096404.pdf

Submitted - 1411.0783v1.pdf

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1411.0783v1.pdf

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Additional details

Additional titles

Alternative title
A structural distortion induced magneto-elastic locking in Sr2IrO4 revealed through nonlinear optical harmonic generation

Identifiers

Eprint ID
51833
Resolver ID
CaltechAUTHORS:20141117-101456748

Related works

Describes
https://arxiv.org/abs/1411.0783 (URL)

Funding

Army Research Office (ARO)
W911NF-13-1-0059
Army Research Office (ARO)
W911NF-13-1-0293
NSF
PHY-1125565
Gordon and Betty Moore Foundation
GBMF1250
NSF
DMR-1255544
NSF
DMR-1005932
NSF
DMR-1265162
Institute for Quantum Information and Matter (IQIM)

Dates

Created
2014-11-17
Created from EPrint's datestamp field
Updated
2021-11-10
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Institute for Quantum Information and Matter