Spin Waves and Dirac Magnons in a Honeycomb Lattice Zig-zag Antiferromagnet BaNi2(AsO4)2

Abstract

The topological properties of massive and massless fermionic quasiparticles have been intensively investigated over the past decade in topological materials without magnetism. Recently, the bosonic analogs of such quasiparticles arising from spin waves have been reported in the two-dimensional (2D) honeycomb lattice ferromagnet/antiferromagnet and the 3D antiferromagnet. Here we use time-of-flight inelastic neutron scattering to study spin waves of the S = 1 honeycomb lattice antiferromagnet BaNi2(AsO4)2, which has a zig-zag antiferromagnetic (AF) ground state identical to that of the Kitaev quantum spin liquid candidate alpha-RuCl3. We determine the magnetic exchange interactions in the zig-zag AF ordered phase, and show that spin waves in BaNi2(AsO4)2 have symmetry-protected Dirac points inside the Brillouin zone boundary. These results provide a microscopic understanding of the zig-zag AF order and associated Dirac magnons in honeycomb lattice magnets, and are also important for establishing the magnetic interactions in Kitaev quantum spin liquid candidates.

References in corpus (13)

• Topological Photonics
• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• Double-Weyl phonons in transition-metal monosilicides
• Dirac magnons in honeycomb ferromagnets
• Kitaev interactions in the Co honeycomb antiferromagnets Na${}_3$Co${}_2$SbO${}_6$ and Na${}_2$Co${}_2$TeO${}_6$
• Zigzag antiferromagnetic ground state with anisotropic correlation lengths in the quasi-2D honeycomb lattice compound Na2Co2TeO6
• Weak-field induced nonmagnetic state in a Co-based honeycomb
• Magnetic field effect on topological spin excitations in CrI${}_3$
• Topological magnon insulator spin excitations in the two-dimensional ferromagnet CrBr${}_3$
• Polarized-neutron investigation of magnetic ordering and spin dynamics in BaCo${}_2$(AsO${}_4$)${}_2$ frustrated honeycomb-lattice magnet
• Temperature dependence of the paramagnetic spin excitations in BaFe${}_2$As${}_2$
• Evolution of magnetic Dirac bosons in a honeycomb lattice
• Investigation of the spin-1 honeycomb antiferromagnet BaNi${}_2$V${}_2$O${}_8$ with easy plane anisotropy

Cited by in corpus (7)

• Excitations in the ordered and paramagnetic states of honeycomb magnet Na2Co2TeO6
• Topological Phases in Magnonics
• Spin wave Hamiltonian and anomalous scattering in NiPS${}_3$
• Easy-plane anisotropic-exchange magnets on a honeycomb lattice: quantum effects and dealing with them
• Understanding the magnetic interactions of the zig-zag honeycomb lattice: Application to $\alpha$-RuCl${}_3$
• Stabilization of zigzag order in NiPS${}_3$ via positive biquadratic interaction
• Spin Wave Dispersion of the van der Waals Antiferromagnet NiPS${}_3$