Photoexcited states of the harmonic honeycomb iridate γ-Li${}_2$IrO${}_3$

Abstract

We report equilibrium and nonequilibrium optical measurements on the recently synthesized "harmonic" honeycomb iridate γ-Li${}_2$IrO${}_3$ (LIO), as well as the layered honeycomb iridate Na${}_2$IrO${}_3$ (NIO). Using Fourier transform infrared microscopy we performed reflectance measurements on LIO, from which we obtained the optical conductivity below 2 eV. In addition we measured the photoinduced changed in reflectance, ΔR, as a function of time, t, temperature, T, and probe field polarization in both LIO and NIO. In LIO, ΔR(t,T) is anisotropic and comprised of three T dependent components. Two of these components are related to the onset of magnetic order and the third is related to a photoinduced population of metastable electronic excited states. In NIO, ΔR(t,T) has a single T dependent component that is strikingly similar to the electronic excitation component of ΔR in LIO. Through analysis and comparison of ΔR(t,T) for two compounds, we extract information on the onset of magnetic correlations at and above the transition temperature in LIO, the bare spin-flip scattering rate in equilibrium, the lifetime of low-lying quasiparticle excitations, and the polarization dependence of optical transitions that are sensitive to magnetic order.

References in corpus (15)

• Novel Jeff = 1/2 Mott State Induced by Relativistic Spin-Orbit Coupling in Sr2IrO4
• Twisted Hubbard Model for Sr2IrO4: Magnetism and Possible High Temperature Superconductivity
• Hyper-honeycomb iridate $\beta$-Li2IrO3 as a platform for Kitaev magnetism
• Long range magnetic ordering in Na${}_2$IrO${}_3$
• Fermi Arcs in a Doped Pseudospin-1/2 Heisenberg Antiferromagnet
• A new spin-anisotropic harmonic honeycomb iridate
• Crystal field splitting and correlation effect on the electronic structure of A2IrO3
• Na2IrO3 as a spin-orbit-assisted antiferromagnetic insulator with a 340 meV gap
• Non-coplanar and counter-rotating incommensurate magnetic order stabilized by Kitaev interactions in $\gamma$-Li2IrO3
• Spiral order in the honeycomb iridate Li2IrO3
• Theory of Magnetic Phase Diagrams in Hyperhoneycomb and Harmonic-honeycomb Iridates
• Unified theory of spiral magnetism in the harmonic-honeycomb iridates α, β, γ Li2IrO3
• Confinement-Deconfinement Transition as an Indication of Spin-Liquid-Type Behavior in Na${}_2$IrO${}_3$
• Analysis of the optical conductivity for A2IrO3 (A = Na, Li) from first principles
• Antiferromagnetic Slater Insulator Phase of Na2IrO3

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• Kitaev magnetism through the prism of lithium iridate
• Magnon-spinon dichotomy in the Kitaev hyperhoneycomb $\beta$-Li${}_2$IrO${}_3$
• Electronic excitations in $\gamma$-Li${}_2$IrO${}_3$
• Tracking local magnetic dynamics via high-energy charge excitations in a relativistic Mott insulator
• Magneto-Elastic Coupling to Coherent Acoustic Phonon Modes in Ferrimagnetic Insulator GdTiO${}_3$
• Competition between magnetic order and charge localization in Na${}_2$IrO${}_3$ thin crystal devices
• The origin of exciton mass in a frustrated Mott insulator Na${}_2$IrO${}_3$
• Ultrafast spin dynamics in the proximate quantum spin liquid α-RuCl3