Published August 15, 2019 | Version Submitted + Published + Supplemental Material
Journal Article Open

Momentum-resolved lattice dynamics of parent and electron-doped Sr_2IrO_4

  • 1. ROR icon University College London
  • 2. ROR icon Brookhaven National Laboratory
  • 3. ROR icon RIKEN
  • 4. ROR icon Ural Federal University
  • 5. ROR icon University of Colorado Boulder
  • 6. ROR icon California Institute of Technology
  • 7. ROR icon University of Geneva

Abstract

The mixing of orbital and spin character in the wave functions of the 5d iridates has led to predictions of strong couplings among their lattice, electronic, and magnetic degrees of freedom. As well as realizing a novel spin-orbit assisted Mott-insulating ground state, the perovskite iridate Sr_2IrO_4 has strong similarities with the cuprate La_2CuO_4, which on doping hosts a charge-density wave that appears intimately connected to high-temperature superconductivity. These phenomena can be sensitively probed through momentum-resolved measurements of the lattice dynamics, made possible by meV-resolution inelastic x-ray scattering. Here we report the first such measurements for both parent and electron-doped Sr_2IrO_4. We find that the low-energy phonon dispersions and intensities in both compounds are well described by the same nonmagnetic density functional theory calculation. In the parent compound, no changes of the phonons on magnetic ordering are discernible within the experimental resolution, and in the doped compound no anomalies are apparent due to charge-density waves. These measurements extend our knowledge of the lattice properties of (Sr_(1−x)La_x)_2IrO_4 and constrain the couplings of the phonons to magnetic and charge order.

Additional Information

© 2019 American Physical Society. Received 24 April 2019; published 19 August 2019. C.D.D. thanks A. Togo for assistance with the PHONOPY calculations. C.D.D. was supported by the Engineering and Physical Sciences Research Council (EPSRC) Centre for Doctoral Training in the Advanced Characterisation of Materials under Grant No. EP/L015277/1. The IXS measurements were supported by the U.S. Department of Energy (DOE), Office of Basic Energy Sciences, Early Career Award Program under Award No. 1047478. The DFT calculations were carried out using high-performance computing resources at Moscow State University [54]. Work at Brookhaven National Laboratory was supported by the U.S. DOE, Office of Science, Office of Basic Energy Sciences, under Contract No. DESC00112704. Work at UCL was supported by the EPSRC under Grants No. EP/N027671/1 and No. EP/N034872/1. Work at Ural Federal University was supported by the Russian Science Foundation under Grant No. 18-12-00185. G.C. was supported by the U.S. National Science Foundation under Grant No. DMR-1712101. The IXS experiments were performed at beamline BL43LXU at the SPring-8 synchrotron with the approval of RIKEN under Proposal No. 20180059.

Attached Files

Published - PhysRevB.100.085131.pdf

Submitted - 1904.10391.pdf

Supplemental Material - Sr214_phonon_PRB_SUPPLEMENTAL.pdf

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Additional details

Additional titles

Alternative title
Momentum-resolved lattice dynamics of parent and electron-doped Sr2IrO4

Identifiers

Eprint ID
97995
Resolver ID
CaltechAUTHORS:20190819-101754313

Related works

Funding

Engineering and Physical Sciences Research Council (EPSRC)
EP/L015277/1
Department of Energy (DOE)
1047478
Department of Energy (DOE)
DE-SC00112704
Engineering and Physical Sciences Research Council (EPSRC)
EP/N027671/1
Engineering and Physical Sciences Research Council (EPSRC)
EP/N034872/1
Russian Science Foundation
18-12-00185
NSF
DMR-1712101
RIKEN
20180059

Dates

Created
2019-08-19
Created from EPrint's datestamp field
Updated
2021-11-16
Created from EPrint's last_modified field

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