Absence of temperature-dependent phonon anomalies in Sr2IrO4 and Sr3Ir2O7

Abstract

Following previous works reporting an anomalous behavior of several zone-center optical phonons across the magnetic transition of square lattice iridates Sr2IrO4 and Sr3Ir2O7, we have investigated the lattice dynamics as a function of momentum in these materials by means of high-resolution inelastic x-ray scattering (IXS). The observed phonon energies and scattering intensities across the Brillouin zone are in excellent agreement with ab-initio lattice dynamical calculations based on non-magnetic density-functional-perturbation theory (DFPT). Our results do not evidence any renormalization of the phonons at finite momentum across the magnetic transition of Sr2IrO4. The only anomalous behavior was detected for the in-plane polarized longitudinal-acoustic phonon branch in Sr3Ir2O7, which anomalously softens towards low temperatures and might be related to anisotropic negative thermal expansion in this compound. No anomalies related to potential charge ordering were observed.

References in corpus (25)

• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• Novel Jeff = 1/2 Mott State Induced by Relativistic Spin-Orbit Coupling in Sr2IrO4
• Extended Phonon Collapse and the Origin of the Charge-Density-Wave in NbSe${}_2$
• Observation of Unconventional Charge Density Wave without Acoustic Phonon Anomaly in Kagome Superconductors AV3Sb5 (A=Rb,Cs)
• Fermi Arcs in a Doped Pseudospin-1/2 Heisenberg Antiferromagnet
• Observation of a $d$-wave gap in electron-doped Sr${}_2$IrO${}_4$
• Giant phonon anomalies and central peak due to charge density wave formation in YBa${}_2$Cu${}_3$O${}_{6.6}$
• Accuracy of generalized gradient approximation functionals for density functional perturbation theory calculations
• The magnetic and crystal structures of Sr2IrO4: A neutron diffraction study
• Non-Fermi-liquid behavior in nearly ferromagnetic metallic SrIrO3 single crystals
• Giant Kohn anomaly and the phase transition in charge density wave ZrTe_3
• Persistent paramagnons deep in the metallic phase of Sr${}_{2-x}$La${}_x$IrO${}_4$
• Two-magnon Raman scattering and pseudospin-lattice interactions in Sr2IrO4 and Sr3Ir2O7
• Pseudospin-lattice coupling in the spin-orbit Mott insulator Sr2IrO4
• A charge density wave-like instability in a doped spin-orbit-assisted weak Mott insulator
• Crossover from coherent to incoherent scattering in spin-orbit dominated Sr2IrO4
• First-order melting of a weak spin-orbit Mott insulator into a correlated metal
• Crystal growth and intrinsic magnetic behavior of Sr${}_2$IrO${}_4$
• Raman scattering study of vibrational and magnetic excitations in Sr${}_{2-x}$La${}_x$IrO${}_4$
• Electrical Control of Structural and Physical Properties via Strong Spin-Orbit Interactions in Sr2IrO4
• Structural investigation of the bilayer iridate Sr3Ir2O7
• Strong Pseudospin-Lattice Coupling in Sr3Ir2O7: Coherent Phonon Anomaly and Negative Thermal Expansion
• Strange semimetal dynamics in SrIrO${}_3$
• Momentum-resolved lattice dynamics of parent and electron-doped Sr${}_2$IrO${}_4$
• Polarized Raman spectroscopy study of metallic $(S{r}_{1-x}L{a}_x{)}_{3}I{r}_2{O}_7$: a consistent picture of disorder-interrupted unidirectional charge order