Scaling behavior and giant field-enhancement of the thermal conductivity in the honeycomb antiferromagnet BaCo2(AsO4)2

Abstract

The layered honeycomb material BaCo${}_2$(AsO${}_4$)${}_2$ (BCAO) is of topical interest because its magnetic state is related to that of the Kitaev magnet $\alpha$-RuCl${}_3$. Using thermal transport to probe how magnetic excitations interact with phonons in the magnetically disordered regime, we have uncovered an unusually large enhancement of the thermal conductivity ${\kappa }_{xx}$ in an in-plane magnetic field $\mathbf{H}$. Just above the Néel temperature $T_{\mathrm{N}}$, a field of 13 T increases ${\kappa }_{xx}$ by a factor $\sim 211$, much larger than reported previously in any magnetic insulator. Interestingly, ${\kappa }_{xx}(H,T)$ exhibits a scaling behavior in the entire magnetically disordered region that surrounds the ordered zigzag state. The ratio $\Delta {\kappa }_{xx}(H,T)/{\kappa }_{xx}(13,T)$, measured throughout the disordered region, collapses to a one-parameter scaling function $\exp (-1/gx)$ (where $x={\mu }_{\mathrm{B}}B/k_{\mathrm{B}}T$ and $g$ is a constant).

8 pages, 4 figures

References in corpus (19)

• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• Pseudospin exchange interactions in d^7 cobalt compounds: Possible realization of the Kitaev model
• The planar thermal Hall conductivity in the Kitaev magnet α-RuCl3
• Weak-field induced nonmagnetic state in a Co-based honeycomb
• Unconventional spin dynamics in the honeycomb-lattice material $\alpha$-RuCl${}_3$: high-field ESR studies
• Geometrical frustration versus Kitaev interactions in BaCo${}_2$(AsO${}_4$)${}_2$
• A magnetic continuum observed by terahertz spectroscopy in a quantum spin liquid candidate BaCo${}_2$(AsO${}_4$)${}_2$
• Large magnetothermal conductivity of HoMnO_3 single crystals and its relation to the magnetic-field induced transitions of magnetic structure
• XY magnetism, Kitaev exchange, and long-range frustration in the $J_{\mathrm{eff}}=1/2$ honeycomb cobaltates
• Magnetic Couplings in Edge-Sharing High-Spin $d^7$ Compounds
• Ab initio guided minimal model for the "Kitaev" material BaCo${}_2$(AsO${}_4$)${}_2$: Importance of direct hopping, third-neighbor exchange and quantum fluctuations
• Nature of Magnetic Excitations in the High-Field Phase of $\alpha$-RuCl${}_3$
• Polarized-neutron investigation of magnetic ordering and spin dynamics in BaCo${}_2$(AsO${}_4$)${}_2$ frustrated honeycomb-lattice magnet
• Giant thermal magnetoconductivity in CrCl${}_3$ and a general model for spin-phonon scattering
• Anomalous thermal expansion and strong damping of the thermal conductivity of NdMnO${}_3$ and TbMnO${}_3$ due to 4f crystal-field excitations
• Phonon thermal transport shaped by strong spin-phonon scattering in a Kitaev material Na${}_2$Co${}_2$TeO${}_6$
• Proximate Dirac spin liquid in honeycomb lattice $J_1$-$J_3$ XXZ model: Numerical study and application to cobaltates
• Hydrostatic pressure effect on Co-based honeycomb magnet BaCo2(AsO4)2
• Intermediate field-induced phase of the honeycomb magnet BaCo${}_2$(AsO${}_4$)${}_2$

Cited by in corpus (1)

• BaCo${}_2$(AsO${}_4$)${}_2$: Strong Kitaev, After All