Quantum Weyl-Heisenberg antiferromagnet

Abstract

Beginning from the conventional square-lattice nearest-neighbor antiferromagnetic Heisenberg model, we allow the $J_x$ and $J_y$ couplings to be anisotropic, with their values depending on the bond orientation. The emergence of anisotropic, bond-dependent, couplings should be expected to occur naturally in most antiferromagnetic compounds which undergo structural transitions that reduce the point-group symmetry at lower temperature. Using the spin-wave approximation, we study the model in several parameter regimes by diagonalizing the reduced Hamiltonian exactly, and computing the edge spectrum and Berry connection vector, which show clear evidence of localized topological charges. We discover phases that exhibit Weyl-type spin-wave dispersion, characterized by pairs of degenerate points and edge states, as well as phases supporting lines of degeneracy. We also identify a parameter regime in which there is an exotic state hosting gapless linear spin-wave dispersions with different longitudinal and transverse spin-wave velocities. Author email info: [email protected] and [email protected]

arXiv comment8 two-column latex pages 9 figures

References in corpus (16)

• Topological Insulators
• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Electronic Structure of Pyrochlore Iridates: From Topological Dirac Metal to Mott Insulator
• Topological Insulators in Three Dimensions
• Weyl and Dirac Semimetals in Three Dimensional Solids
• Quantum Simulation of Antiferromagnetic Spin Chains in an Optical Lattice
• Topological spin excitations in honeycomb ferromagnet CrI${}_3$
• Weyl magnons in breathing pyrochlore antiferromagnets
• Observation of canted antiferromagnetism with ultracold fermions in an optical lattice
• Topological excitations in the ferromagnetic Kitaev-Heisenberg model
• Anomalous Thermal Hall Effect in an Insulating van der Waals Magnet VI3
• Weyl magnons in pyrochlore antiferromagnets with all-in-all-out orders
• Squaring the fermion: The threefold way and the fate of zero modes
• Topological magnons on the triangular kagome lattice
• Topological Weyl magnons and thermal Hall effect in layered honeycomb ferromagnets
• Weyl Nodal-Ring Semimetallic Behavior and Topological Superconductivity in Crystalline Forms of Su-Schrieffer-Heeger Chains

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