Magnetic excitations of the field induced states in BaCo2(AsO4)2 probed by time-domain terahertz spectroscopy

Abstract

Searching for Kitaev quantum spin liquid (QSL) is a fascinating and challenging problem. Much effort has been devoted to honeycomb lattice candidates with strong spin-orbit coupling in 5d-electron iridates and 4delectron RuCl3. Recently, theoretical studies suggested that the 3d7 Co-based honeycomb materials with high spin state S=3/2 and effective orbital angular momentum L=1 could also be promising candidates of Kitaev QSL. One of the candidates, BaCo2(AsO4)2, was revisited recently. The long range magnetic order in BaCo2(AsO4)2 can be suppressed by very weak in-plane magnetic field, suggesting its proximity to Kitaev QSL. Here we perform time domain terahertz spectroscopy measurement to study the magnetic excitations on BaCo2(AsO4)2. We observe different magnon excitations upon increasing external magnetic field. In particular, the system is easily driven to a field-polarized paramagnetic phase, after the long range magnetic order is suppressed by a weak field Hc 2. The spectra beyond Hc2 are dominated by single magnon and two magnon excitations without showing signature of QSL. We discuss the similarity and difference of the excitation spectra between BaCo2(AsO4)2 and the widely studied Kitaev QSL candidate RuCl3.

6 pages, 4 figures

References in corpus (18)

• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• On the Origin of Zigzag Magnetic Order in Iridium Oxide Na2IrO3
• Pseudospin exchange interactions in d^7 cobalt compounds: Possible realization of the Kitaev model
• Kitaev-Heisenberg Hamiltonian for High-Spin $d^7$ Mott Insulators
• Kitaev Spin Liquid in 3d Transition Metal Compounds
• Magnetic Excitations and Continuum of a Field-Induced Quantum Spin Liquid in $\alpha$-RuCl${}_3$
• Field-induced quantum spin disordered state in spin-1/2 honeycomb magnet Na2Co2TeO6
• Honeycomb-lattice Heisenberg-Kitaev model in a magnetic field: Spin canting, metamagnetism, and vortex crystals
• Kitaev interactions in the Co honeycomb antiferromagnets Na${}_3$Co${}_2$SbO${}_6$ and Na${}_2$Co${}_2$TeO${}_6$
• Magnetic properties of the honeycomb oxide Na${}_2$Co${}_2$TeO${}_6$
• Magnetic anisotropy in the Kitaev model systems Na2IrO3 and RuCl3
• Weak-field induced nonmagnetic state in a Co-based honeycomb
• Spin-orbit phase behaviors of Na2Co2TeO6 at low temperatures
• Magnetic order in single crystals of Na3Co2SbO6 with a honeycomb arrangement of 3d${}^7$ Co${}^{2+}$ ions
• Unconventional spin dynamics in the honeycomb-lattice material $\alpha$-RuCl${}_3$: high-field ESR studies
• 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
• Competing Antiferromagnetic-Ferromagnetic States in $d^7$ Kitaev Honeycomb Magnet

Cited by in corpus (25)

• Geometrical frustration versus Kitaev interactions in BaCo${}_2$(AsO${}_4$)${}_2$
• Beyond Kitaev physics in strong spin-orbit coupled magnets
• A magnetic continuum observed by terahertz spectroscopy in a quantum spin liquid candidate BaCo${}_2$(AsO${}_4$)${}_2$
• Magnetic Couplings in Edge-Sharing High-Spin $d^7$ Compounds
• Experimental signatures of quantum and topological states in frustrated magnetism
• Ab initio guided minimal model for the "Kitaev" material BaCo${}_2$(AsO${}_4$)${}_2$: Importance of direct hopping, third-neighbor exchange and quantum fluctuations
• Triple-q order in Na${}_2$Co${}_2$TeO${}_6$ from proximity to hidden-SU(2)-symmetric point
• Spin vestigial orders in extended Heisenberg-Kitaev models near hidden SU(2) points: Application to Na${}_2$Co${}_2$TeO${}_6$
• Comparative Raman Scattering Study of Crystal Field Excitations in Co-based Quantum Magnets
• Field and Polarization Dependent Quantum Spin Dynamics in Honeycomb Magnet Na${}_2$Co${}_2$TeO${}_6$: Magnetic Excitations and Continuum
• Single-crystal study of the honeycomb XXZ magnet BaCo${}_2$(PO${}_4$)${}_2$ in magnetic fields
• Ferrimagnetism from triple-q order in Na${}_2$Co${}_2$TeO${}_6$
• Active orbital degree of freedom and potential spin-orbit-entangled moments in Kitaev magnet candidate BaCo${}_2$(AsO${}_4$)${}_2$
• BaCo${}_2$(AsO${}_4$)${}_2$: Strong Kitaev, After All
• Probing critical spin fluctuations with a composite magnetoelectric method: A case study on a Kitaev spin liquid candidate Na${}_3$Co${}_2$SbO${}_6$
• On the multi-$\mathbf{q}$ characteristics of magnetic ground states of honeycomb cobalt oxides
• Hydrostatic pressure effect on Co-based honeycomb magnet BaCo2(AsO4)2
• Disorder-induced excitation continuum in a spin-1/2 cobaltate on a triangular lattice
• Proximity-induced sequence of field transitions in Kitaev candidate BaCo${}_2$(AsO${}_4$)${}_2$
• Spin-orbit entangled moments and magnetic exchange interactions in cobalt-based honeycomb magnets BaCo${}_2$($X$O${}_4$)${}_2$ ($X$ = P, As, Sb)
• Ground state and magnetic transitions of the orthorhombic antiferromagnet CaCo${}_2$TeO${}_6$
• Ferrimagnetism from quantum fluctuations in Kitaev materials
• Trigonal distortion in the Kitaev candidate honeycomb magnet BaCo2(AsO4)2
• Direct measurement of photoinduced transient conducting state in multilayer 2H-MoTe2
• Projected Holstein-Primakoff boson representation of quantum spins for spin wave theory