Raman spectroscopy of anyons in generic Kitaev spin liquids

Abstract

Optical probes have emerged as versatile tools for detecting exotic fractionalized phases in quantum materials. We calculate the low-energy Raman response arising from mobile, interacting Ising anyons (or visons) in the chiral Kitaev spin liquid perturbed by symmetry allowed interactions - a phase relevant to \rucl. under a magnetic field. At zero temperature, the two-anyon continuum response shows a leading power-law scaling of the intensity near the onset of the signal: $I(\omega )\sim (\omega -E_{2\sigma }^0{)}^{\frac{1}{8}}$ for linear and parallel-circular polarization channels, where $E_{2\sigma }^0$ is the two-particle gap. Strong corrections due to short-range interactions arise at order $\frac{1}{4}$. For cross-circularly polarized channels, the scaling is given by $I(\omega )\sim (\omega -E_{2\sigma }^0{)}^{|l\pm 1/8|}$, where the value of $l=0,1,2$ is determined by the number of minima in the single anyon dispersion. The exponents are directly related to the topological spin of Ising anyons ${\theta }_{\sigma }=\frac{\pi }{8}$, describing their exchange statistics. Our theory generalizes to spectral probes of anyonic quasiparticles with multiple band minima in other quantum liquids. Interaction between anyons may also induce bound-states, resulting in sharp peaks that show strong polarization dependence.

13 pages of main text, 8 figures

References in corpus (12)

• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• Scattering Continuum and Possible Fractionalized Excitations in $\alpha$-RuCl${}_3$
• Raman Scattering Signatures of Kitaev Spin Liquids in A${}_2$ IrO${}_3$ Iridates
• Dynamics of visons and thermal Hall effect in perturbed Kitaev models
• Variational study of the Kitaev-Heisenberg-Gamma model
• Dynamic fingerprint of fractionalized excitations in single-crystalline Cu${}_3$Zn(OH)${}_6$FBr
• Direct optical probe of magnon topology in two-dimensional quantum magnets
• Nature of visons in the perturbed ferromagnetic and antiferromagnetic Kitaev honeycomb models
• Signatures of Kitaev interactions in the van der Waals ferromagnet VI3
• Spectra of a Gapped Quantum Spin Liquid with a Strong Chiral Excitation on the Triangular Lattice
• Gauge Field Dynamics in Multilayer Kitaev Spin Liquids
• Chiral excitations and the intermediate-field spin-liquid regime in the Kitaev magnet $\alpha$-RuCl${}_3$