Field evolution of magnons in $\alpha$-RuCl${}_3$ by high-resolution polarized terahertz spectroscopy

Abstract

The Kitaev quantum spin liquid (KSL) is a theoretically predicted state of matter whose fractionalized quasiparticles are distinct from bosonic magnons, the fundamental excitation in ordered magnets. The layered honeycomb antiferromagnet $\alpha$-RuCl${}_3$ is a KSL candidate material, as it can be driven to a magnetically disordered phase by application of an in-plane magnetic field, with $H_c\sim 7$ T. Here we report a detailed characterization of the magnetic excitation spectrum of this material by high-resolution time-domain terahertz (THz) spectroscopy. We observe two sharp magnon resonances whose frequencies and amplitudes exhibit a discontinuity as a function of applied magnetic field, as well as two broader peaks at higher energy. Below the Néel temperature, we find that linear spin wave theory can account for all of these essential features of the spectra when a $C_3$-breaking distortion of the honeycomb lattice and the presence of structural domains are taken into account.

arXiv comment8 pages, 5 figures in the main text. Appendices are included at the end of the article

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Cited by in corpus (48)

• Kitaev quantum spin liquid - concept and materialization
• Kitaev interactions in the Co honeycomb antiferromagnets Na${}_3$Co${}_2$SbO${}_6$ and Na${}_2$Co${}_2$TeO${}_6$
• Finite field regime for a quantum spin liquid in $\alpha$-RuCl${}_3$
• Rethinking $\alpha$-RuCl${}_3$
• Magnon-phonon hybridization in quasi-2D antiferromagnet MnPSe${}_3$
• Graphene/$\alpha$-RuCl${}_3$: An Emergent 2D Plasmonic Interface
• Dynamical and thermal magnetic properties of the Kitaev spin liquid candidate $\alpha$-RuCl${}_3$
• High-Field Quantum Disordered State in $\alpha$-RuCl3: Spin Flips, Bound States, and a Multi-Particle Continuum
• Identification of Magnetic Interactions and High-field Quantum Spin Liquid in $\alpha$-RuCl${}_3$
• The range of non-Kitaev terms and fractional particles in RuCl${}_3$
• Thermodynamic perspective on the field-induced behavior of $\alpha$-RuCl${}_3$
• Signatures of low-energy fractionalized excitations in $\alpha$-RuCl${}_3$ from field-dependent microwave absorption
• Magnetic anisotropy reversal driven by structural symmetry-breaking in monolayer α-RuCl3
• Magnetic Field Induced Competing Phases in Spin-Orbital Entangled Kitaev Magnets
• Nature of Magnetic Excitations in the High-Field Phase of $\alpha$-RuCl${}_3$
• Deriving models for the Kitaev spin-liquid candidate material $\alpha$-RuCl${}_3$ from first principles
• The interplay of Dzyaloshinskii-Moriya and Kitaev interactions for magnonic properties of Heisenberg-Kitaev honeycomb ferromagnets
• Kitaev honeycomb models in magnetic fields: Dynamical response and hidden symmetries
• Two-step gap opening across the quantum critical point in a Kitaev honeycomb magnet
• Origin of oscillatory structures in the magnetothermal conductivity of the putative Kitaev magnet $\alpha$-RuCl${}_3$
• Time-Domain Terahertz Spectroscopy in High Magnetic Fields
• Magnetic field-dependent low-energy magnon dynamics in $\alpha$-RuCl3
• Kitaev Quantum Spin Liquids
• THz excitations in α-RuCl3: Majorana fermions, rigid-plane shear and compression modes
• On the saw-tooth torque in anisotropic $j_{\mathrm{eff}}=1/2$ magnets: Application to $\alpha$-RuCl${}_3$
• Extraction of the interaction parameters for $\alpha -$RuCl${}_3$ from neutron data using machine learning
• Scattering Signatures of Bond-Dependent Magnetic Interactions
• Thermal spin dynamics of Kitaev magnets $-$ scattering continua and magnetic field induced phases within a stochastic semiclassical approach
• The Saga of $\alpha$-RuCl${}_3$: Parameters, Models, and Phase Diagrams
• Photoinduced Floquet topological magnons in Kitaev magnets
• Field and Polarization Dependent Quantum Spin Dynamics in Honeycomb Magnet Na${}_2$Co${}_2$TeO${}_6$: Magnetic Excitations and Continuum
• Sub-gap optical response across the structural phase transition in van der Waals layered α-RuCl${}_3$
• Field evolution of low-energy excitations in the hyperhoneycomb magnet $\beta$-Li${}_2$IrO${}_3$
• Proximate Kitaev system for an intermediate magnetic phase in in-plane magnetic fields
• Magnetic terahertz resonances above the Néel temperature in the frustrated kagome antiferromagnet averievite
• Neutron spectroscopy evidence for a possible magnetic-field-induced gapless quantum-spin-liquid phase in a Kitaev material $\alpha$-RuCl${}_3$
• Spin Waves and Dirac Magnons in a Honeycomb Lattice Zig-zag Antiferromagnet BaNi2(AsO4)2
• Light-induced magnetization driven by interorbital charge motion in a spin-orbit assisted Mott insulator alpha-RuCl3
• Differentiable programming tensor networks for Kitaev magnets
• Phonon Dynamics in the Generalized Kitaev Spin Liquid
• Probing critical spin fluctuations with a composite magnetoelectric method: A case study on a Kitaev spin liquid candidate Na${}_3$Co${}_2$SbO${}_6$
• Kitaev quasiparticles in a proximate spin liquid: A many-body localization perspective
• High-field quantum spin liquid transitions and angle-field phase diagram of Kitaev magnet $\alpha$-RuCl${}_3$
• Field tuning Kitaev systems for spin fractionalization and topological order
• First-principles study of bulk stacking, $J_{\mathrm{eff}}$ picture, magnetic Hamiltonian, $g$ factors, and structural distortions of $\alpha$-RuCl${}_3$
• High-accuracy evaluation of non-thermal magnetic states beyond spin-wave theory: applications to higher-energy states
• Magnetostriction in the $J$-$K$-$\Gamma$ model: Application of the numerical linked cluster expansion
• Anomalous and Anisotropic Nonlinear Susceptibility in the Proximate Kitaev Magnet $\alpha$-RuCl${}_3$