Order-by-disorder from Schwinger bosons in a frustrated honeycomb ferromagnet

Abstract

The cobalt-based honeycomb magnet BaCo${}_2$(AsO${}_4$)${}_2$ (BCAO) has recently emerged as a promising platform for frustrated magnetism beyond conventional paradigms. Neutron-scattering experiments and first-principles calculations have revealed an unexpected double-zigzag (dZZ) magnetically ordered ground state, whose microscopic origin remains under active debate. Here, we revisit this problem within a ferro--antiferromagnetic $J_1$--$J_3$ Heisenberg model on the honeycomb lattice using a generalized Schwinger-boson mean-field theory (gSBMFT) that treats ferromagnetic and antiferromagnetic interactions on equal footing. This approach, combined with exact diagonalization (ED), allows us to demonstrate the emergence of the dZZ phase in a narrow parameter range, stabilized by quantum fluctuations through an order-by-disorder mechanism, in good agreement with recent density-matrix renormalization-group (DMRG) results. We further characterize the associated magnetic excitations and discuss their relevance to recent inelastic neutron-scattering (INS) measurements on BCAO.

arXiv comment12 pages, 8 figures

References in corpus (38)

• Kitaev-Heisenberg Model on Honeycomb Lattice: Possible Exotic Phases in Iridium Oxides $A_2$IrO${}_3$
• Majorana quantization and half-integer thermal quantum Hall effect in a Kitaev spin liquid
• Half-integer quantized anomalous thermal Hall effect in the Kitaev material $\alpha$-RuCl${}_3$
• Spin Liquid States on the Triangular and Kagome Lattices: A Projective Symmetry Group Analysis of Schwinger Boson States
• Kitaev interactions in the Co honeycomb antiferromagnets Na${}_3$Co${}_2$SbO${}_6$ and Na${}_2$Co${}_2$TeO${}_6$
• Schwinger Boson Mean Field Theories of Spin Liquid States on Honeycomb Lattice: Projective Symmetry Group Analysis and Critical Field Theory
• A Schwinger-boson approach to the kagome with Dzyaloshinskii-Moriya interactions: phase diagram and dynamical structure factors
• Electronic Structure of the Kitaev Material $\alpha$-${\text{RuCl}}_3$ Probed by Photoemission and Inverse Photoemission Spectroscopies
• Schwinger-boson approach to quantum spin systems: Gaussian fluctuactions in the "natural" gauge
• Dynamical structure factor of the triangular antiferromagnet: the Schwinger boson theory beyond the mean field approach
• XY magnetism, Kitaev exchange, and long-range frustration in the $J_{\mathrm{eff}}=1/2$ honeycomb cobaltates
• Schwinger boson mean field theory of the Heisenberg Ferrimagnetic Spin Chain
• Exotic disordered phases in the quantum $J_1-J_2$ model on the honeycomb lattice
• Chiral spin liquid on kagome antiferromagnet induced by Dzyaloshinskii-Moriya interaction
• Variational study of J1-J2 Heisenberg model on Kagome lattice using projected Schwinger boson wave functions
• Ab initio guided minimal model for the "Kitaev" material BaCo${}_2$(AsO${}_4$)${}_2$: Importance of direct hopping, third-neighbor exchange and quantum fluctuations
• A test of the bosonic spinon theory for the triangular antiferromagnet spectrum
• Non-Kitaev vs. Kitaev Honeycomb Cobaltates
• Polarized-neutron investigation of magnetic ordering and spin dynamics in BaCo${}_2$(AsO${}_4$)${}_2$ frustrated honeycomb-lattice magnet
• Unusual magnetic phases in the strong interaction limit of two-dimensional topological band insulators in transition metal oxides
• Role of quantum fluctuations on spin liquids and ordered phases in the Heisenberg model on the honeycomb lattice
• Schwinger boson spin liquid states on square lattice
• Low temperature properties of the triangular-lattice antiferromagnet: a bosonic spinon theory
• Quantum spin liquid ground states of the Heisenberg-Kitaev model on the triangular lattice
• Spin structure factors of chiral quantum spin liquids on the kagome lattice
• Evidence of Two-Spinon Bound States in the Magnetic Spectrum of Ba${}_3$CoSb${}_2$O${}_9$
• Quantum Phases in the Honeycomb-Lattice $J_1$--$J_3$ Ferro-Antiferromagnetic Model
• Projective symmetry group classification of chiral ${\mathbb{Z}}_2$ spin liquids on the pyrochlore lattice: application to the spin-$1/2$ XXZ Heisenberg model
• Schwinger boson theory of ordered magnets
• Ferromagnetic frustrated spin systems on the square lattice: a Schwinger boson study
• Schwinger Boson mean field theory of kagome Heisenberg antiferromagnet with Dzyaloshinskii-Moriya interaction
• $\require{mhchem}$Quantum paramagnetism in the decorated square-kagome antiferromagnet $\ce{Na6Cu7BiO4(PO4)4Cl3}$
• Schwinger boson theory of the J1,J2=J3 kagome antiferromagnet
• Heisenberg model with Dzyaloshinskii-Moriya interaction: A Schwinger boson study
• BaCo${}_2$(AsO${}_4$)${}_2$: Strong Kitaev, After All
• Proximity-induced sequence of field transitions in Kitaev candidate BaCo${}_2$(AsO${}_4$)${}_2$
• Chiral bosonic quantum spin liquid in the integer-spin Heisenberg-Kitaev model
• Bond-dependent interactions and ill-ordered state in the honeycomb cobaltate BaCo${}_2$(AsO${}_4$)${}_2$