Spin dynamics and continuum spectra of the honeycomb J1-J2 antiferromagnetic Heisenberg model

Abstract

We employ the spin cluster perturbation theory to investigate the dynamical properties of the antiferromagnetic $J_1$-$J_2$ Heisenberg model on the honeycomb lattice. We obtain the excitation spectra for all possible phases in the phase diagram, including the Néel phase, plaquette valence-bond-solid phase, dimer valence-bond-solid phase and stripe antiferromagnetic phase. In the Néel phase, besides the obvious renormalization of the magnon dispersion, we find that the spectrum exhibits a dome-shaped broad continuum around the second Brillouin zone (BZ) and the additional strong continuum close to the corner of the BZ. In the valence-bond-solid phases, the spectra are dominated by a strong broad continuum all the way down to below $J_1$ coexisting with the lowest-energy triplon modes characterizing the plaquette and dimer phases. We ascribe this strong broad continuum and the additional continuum close to the BZ corner in the Néel phase to the contributions of fractionalized spinon excitations. In the stripe phase, a clear difference from the linear spin wave approximation is that the spectrum is gapped at the $M$ point while that obtained by the latter is gapless due to the strong quantum fluctuations. We point out that the features observed in the Néel phase are consistent with the recent neutron scattering experiments on YbCl${}_3$ and YbBr${}_3$.

8 pages, 6 figures

References in corpus (16)

• "Deconfined" quantum critical points
• Quantum criticality beyond the Landau-Ginzburg-Wilson paradigm
• Quantum magnetism and criticality
• Spontaneous Magnon Decays
• Fractional excitations in the square-lattice quantum antiferromagnet
• Anomalous High-Energy Spin Excitations in La2CuO4
• Mott Physics and Topological Phase Transition in Correlated Dirac Fermions
• The J1-J2 model: First order phase transition versus deconfinement of spinons
• Quantum dynamics and entanglement of spins on a square lattice
• Nearly deconfined spinon excitations in the square-lattice spin-1/2 Heisenberg antiferromagnet
• Weak plaquette valence bond order in the $S=1/2$ honeycomb $J_1-J_2$ Heisenberg model
• The frustrated Heisenberg antiferromagnet on the honeycomb lattice: A candidate for deconfined quantum criticality
• Competition between spin liquids and valence-bond order in the frustrated spin-$1/2$ Heisenberg model on the honeycomb lattice
• Second-order quantum corrections for the frustrated, spatially anisotropic, spin-1/2 Heisenberg antiferromagnet on a square lattice
• Phase diagram of a frustrated spin-$\frac{1}{2}$ $J_1$--$J_2$ $XXZ$ model on the honeycomb lattice
• Spin-wave thermodynamics of square-lattice antiferromagnets revisited

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• Quantum decay of magnons in the unfrustrated honeycomb Heisenberg model
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