Isospin-phonon coupling and Fano-interference in spin-orbit Mott insulator Sr2IrO4

Abstract

The isospin-phonon coupling in Sr2IrO4 is investigated by temperature dependent phonon Raman scattering. Anomalous behavior in the frequency of all studied optical phonons is observed below the magnetic transition temperature TN ~240 K. The strongest effect is detected for the A1g mode at 272 cm-1 associated with the modulation of the Ir-O-Ir bond angle. Additionally, the A1g mode at 560 cm-1 shows a Fano asymmetric lineshape sensitive to TN, supporting the existence of low-energy (~70 meV) electronic excitations that are renormalized by the magnetic order. These results reveal new aspects of the interaction between the crystal lattice and electronic degrees of freedom in this spin-orbit entangled Mott insulator.

arXiv comment5 pages and 6 figures

References in corpus (16)

• 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
• Mott physics and band topology in materials with strong spin-orbit interaction
• Lattice-Driven Magnetoresistivity and Metal-Insulator Transition in Single-Layered Iridates
• The Challenge of Spin-Orbit-Tuned Ground States in Iridates
• Magnetic couplings, optical spectra, and spin-orbit exciton in 5d electron Mott insulator Sr2IrO4
• Anisotropic Magnetic Couplings and Structure-Driven Canted to Collinear Transitions in Spin-orbit Coupled Sr2IrO4
• Two-magnon Raman scattering and pseudospin-lattice interactions in Sr2IrO4 and Sr3Ir2O7
• Pseudospin-lattice coupling in the spin-orbit Mott insulator Sr2IrO4
• Giant spin-phonon-electronic coupling in a 5d oxide
• Measurement of the internal magnetic field in the correlated iridates Ca${}_4$IrO${}_6$, Ca${}_5$Ir${}_3$O${}_{12}$, Sr${}_3$Ir${}_2$O${}_7$ and Sr${}_2$IrO${}_4$
• Large spin-phonon coupling and magnetically-induced phonon anisotropy in Sr$M$O${}_3$ perovskites ($M$=V,Cr,Mn,Fe,Co)
• Crossover from coherent to incoherent scattering in spin-orbit dominated Sr2IrO4
• Raman scattering study of vibrational and magnetic excitations in Sr${}_{2-x}$La${}_x$IrO${}_4$
• Spin-Electron-Phonon Excitation in Re-based Half-Metallic Double Perovskites
• First-order structural transition and pressure-induced lattice/phonon anomalies in Sr${}_2$IrO${}_4$

Cited by in corpus (3)

• Anisotropic Lattice Compression and Pressure-Induced Electronic Phase Transitions in Sr${}_2$IrO${}_4$
• Evolution of electronic and magnetic properties of Sr${}_2$IrO${}_4$ under strain
• Quantum Criticality in a Layered Iridate