Footprints of the Kitaev spin liquid in the Fano lineshapes of the Raman active optical phonons

Abstract

We develop a theoretical description of the Raman spectroscopy in the spin-phonon coupled Kitaev system and show that it can provide intriguing observable signatures of fractionalized excitations characteristic of the underlying spin liquid phase. In particular, we obtain the explicit form of the phonon modes and construct the coupling Hamiltonians based on $D_{3d}$ symmetry. We then systematically compute the Raman intensity and show that the spin-phonon coupling renormalizes phonon propagators and generates the salient Fano linshape. We find that the temperature evolution of the Fano lineshape displays two crossovers, and the low temperature crossover shows pronounced magnetic field dependence. We thus identify the observable effect of the Majorana fermions and the $Z_2$ gauge fluxes encoded in the Fano lineshape. Our results explain several phonon Raman scattering experiments in the candidate material $\alpha$-RuCl${}_3$.

arXiv comment15 pages, 7 figures

References in corpus (45)

• Anyons in an exactly solved model and beyond
• Majorana quantization and half-integer thermal quantum Hall effect in a Kitaev spin liquid
• Proximate Kitaev Quantum Spin Liquid Behaviour in α-RuCl${}_3$
• $\alpha$-RuCl3: a Spin-Orbit Assisted Mott Insulator on a Honeycomb Lattice
• Neutron tomography of magnetic Majorana fermions in a proximate quantum spin liquid
• Inelastic Light Scattering From Correlated Electrons
• Models and Materials for Generalized Kitaev Magnetism
• Scattering Continuum and Possible Fractionalized Excitations in $\alpha$-RuCl${}_3$
• Magnetic order in $\alpha$-RuCl${}_3$: a honeycomb lattice quantum magnet with strong spin-orbit coupling
• Dynamics of a two-dimensional quantum spin liquid: signatures of emergent Majorana fermions and fluxes
• Excitations in the field-induced quantum spin liquid state of alpha-RuCl3
• Fermionic response from fractionalization in an insulating two-dimensional magnet
• Thermal fractionalization of quantum spins in a Kitaev model: $T$-linear specific heat and coherent transport of Majorana fermions
• Doping a spin-orbit Mott Insulator: Topological Superconductivity from the Kitaev-Heisenberg Model and possible application to (Na2/Li2)IrO3
• Raman Scattering Signatures of Kitaev Spin Liquids in A${}_2$ IrO${}_3$ Iridates
• Dynamics of Fractionalization in Quantum Spin Liquids
• Relation between Kitaev magnetism and structure in $\alpha$-RuCl${}_3$
• Quantization of the thermal Hall conductivity at small Hall angles
• Magnon bound states vs. anyonic Majorana excitations in the Kitaev honeycomb magnet $\alpha$-RuCl${}_3$
• Approximately quantized thermal Hall effect of chiral liquids coupled to phonons
• Antiferromagnetic resonance and terahertz continuum in $\alpha -$RuCl${}_3$
• Resolving continua of fractional excitations by spinon echo in THz 2D coherent spectroscopy
• Resonant two-magnon Raman scattering in antiferromagnetic insulators
• High-Field Quantum Disordered State in $\alpha$-RuCl3: Spin Flips, Bound States, and a Multi-Particle Continuum
• Resonant inelastic X-ray scattering response of the Kitaev honeycomb model
• Quantum spin liquid at finite temperature: proximate dynamics and persistent typicality
• Raman signature of the U(1) Dirac spin-liquid state in spin-1/2 kagome system
• Theory of Raman response in three-dimensional Kitaev spin liquids: application to $\beta -$ and $\gamma -$Li${}_2$IrO${}_3$ compounds
• The range of non-Kitaev terms and fractional particles in RuCl${}_3$
• Phonon dynamics in the Kitaev spin liquid
• Interacting non-Abelian anyons as Majorana fermions in the honeycomb lattice model
• Raman evidence for dimerization and Mott collapse in $\alpha$-RuCl${}_3$ under pressures
• Magnetoelastic coupling and effects of uniaxial strain in $\alpha$-RuCl${}_3$ from first principles
• Phonon renormalization in the Kitaev quantum spin liquid
• Polarization-resolved Raman spectroscopy of α-RuCl3 and evidence of room temperature two-dimensional magnetic scattering
• Raman scattering in a Heisenberg {\boldmath $S=1/2$} antiferromagnet on the triangular lattice
• Resonant Raman scattering theory for Kitaev models and their Majorana fermion boundary modes
• Observing spin fractionalization in the Kitaev spin liquid via temperature evolution of indirect resonant inelastic x-ray scattering
• Temperature evolution of the phonon dynamics in the Kitaev spin liquid
• Further insights into the thermodynamics of the Kitaev honeycomb model
• Fingerprints of quantum spin ice in Raman scattering
• Raman scattering in a Heisenberg S=1/2 antiferromagnet on the anisotropic triangular lattice
• Raman scattering in correlated thin films as a probe of chargeless surface states
• Optical phonons coupled to a Kitaev spin liquid
• Non-Loudon-Fleury Raman scattering in spin-orbit coupled Mott insulators

Cited by in corpus (9)

• Thermal Hall Effect in the Kitaev-Heisenberg System with Spin-Phonon Coupling
• Phonon Dynamics in the Generalized Kitaev Spin Liquid
• Fluctuating Fractionalized Spins in Quasi Two-dimensional Magnetic V0.85PS3
• Signatures of non-Loudon-Fleury Raman scattering in the Kitaev magnet $\beta$-Li${}_2$IrO${}_3$
• Polar phonons and magnetic excitations in the antiferromagnet CoF${}_2$
• Phonon Dynamics in the Chiral Kitaev Spin Liquid
• Sound attenuation in the hyperhoneycomb Kitaev spin liquid
• Signatures of fractionalization in the optical phonons of hyperhoneycomb Kitaev magnet $\beta$-Li${}_2$IrO${}_3$
• Magnetostriction in the $J$-$K$-$\Gamma$ model: Application of the numerical linked cluster expansion