Effective Magnetic Hamiltonian at Finite Temperatures for Rare Earth Chalcogenides

Abstract

Alkali metal rare-earth chalcogenide $ARECh2$ (A=alkali or monovalent metal, RE=rare earth, Ch=O, S, Se, Te), is a large family of quantum spin liquid (QSL) candidates we discovered recently. Unlike $YbMgGaO4$, most members in the family except for the oxide ones, have relatively small crystalline electric-field (CEF) excitation levels, particularly the first ones. This makes the conventional Curie-Weiss analysis at finite temperatures inapplicable and CEF excitations may play an essential role in understanding the low-energy spin physics. Here we considered an effective magnetic Hamiltonian incorporating CEF excitations and spin-spin interactions, to accurately describe thermodynamics in such a system. By taking $NaYbSe2$ as an example, we were able to analyze magnetic susceptibility, magnetization under pulsed high fields and heat capacity in a systematic and comprehensive way. The analysis allows us to produce accurate anisotropic exchange coupling energies and unambiguously determine a crossover temperature ($\sim$25 K in the case of $NaYbSe2$), below which CEF effects fade away and pure spin-spin interactions stand out. We further validated the effective picture by successfully explaining the anomalous temperature dependence of electron spin resonance (ESR) spectral width. The effective scenario in principle can be generalized to other rare-earth spin systems with small CEF excitations.

arXiv comment7 pages, 4 figures + Supplementary Information

References in corpus (29)

• Mantid - Data Analysis and Visualization Package for Neutron Scattering and $\mu SR$ Experiments
• Spin Dynamics of the Spin-1/2 Kagome Lattice Antiferromagnet ZnCu_3(OH)_6Cl_2
• Rare-earth triangular lattice spin liquid: a single-crystal study of YbMgGaO${}_4$
• Gapless quantum spin liquid ground state in the two-dimensional spin-1/2 triangular antiferromagnet YbMgGaO${}_4$
• Field-tunable quantum disordered ground state in the triangular lattice antiferromagnet NaYbO${}_2$
• Dzyaloshinsky-Moriya Anisotropy in the Spin-1/2 Kagomé Compound ZnCu${}_3$(OH)${}_6$Cl${}_2$
• Rare-earth chalcogenides: A large family of triangular lattice spin liquid candidate
• Crystalline Electric Field Randomness in the Triangular Lattice Spin-Liquid YbMgGaO${}_4$
• NaYbS${}_2$ - a new planar spin-$\frac{1}{2}$ triangular-lattice magnet and putative spin liquid
• Gapless spin-liquid state in the structurally disorder-free triangular antiferromagnet NaYbO${}_2$
• An anisotropic spin model of strong spin-orbit-coupled triangular antiferromagnets
• Anisotropic field-induced ordering in the triangular-lattice quantum spin liquid NaYbSe${}_2$
• Field-induced instability of the quantum-spin-liquid ground state in the $J_{\mathrm{eff}}=\frac{1}{2}$ triangular-lattice compound NaYbO${}_2$
• Quantum spin liquid ground state in the disorder free triangular lattice NaYbS${}_2$
• Field-induced magnetic transition and spin fluctuation in quantum spin liquid candidate CsYbSe${}_2$
• Orbital frustration at the origin of the magnetic behavior in LiNiO2
• The Spinon Fermi Surface U(1) Spin Liquid in a Spin-Orbit-Coupled Triangular Lattice Mott Insulator YbMgGaO4
• Crystalline Electric-Field Excitations in Quantum Spin Liquids Candidate $NaYbS{e}_2$
• The effect of spin-orbit coupling on the effective-spin correlation in YbMgGaO4
• Crystal field states of Tb3+ in the pyrochlore spin liquid Tb2Ti2O7 from neutron spectroscopy
• Mott Transition and Superconductivity in Quantum Spin Liquid Candidate NaYbSe${}_2$
• Partial up-up-down order with the continuously distributed order parameter in the triangular antiferromagnet TmMgGaO4
• Absence of zero-point entropy in a triangular Ising antiferromagnet
• Effect of Chemical Pressure on the Crystal Electric Field States of Erbium Pyrochlore Magnets
• Electron Spin Resonance on the spin-1/2 triangular magnet NaYbS2
• Synthesis, magnetization and heat capacity of triangular lattice materials NaErSe${}_2$ and KErSe${}_2$
• Single-site magnetic anisotropy governed by inter-layer cation charge imbalance in triangular-lattice AYbX${}_2$
• Long-range magnetic order in the $\tilde{S}=1/2$ triangular lattice antiferromagnet KCeS${}_2$
• Pressure induced metallization and possible unconventional superconductivity in spin liquid $NaYbS{e}_2$

Cited by in corpus (20)

• Experimental signatures of quantum and topological states in frustrated magnetism
• Non-linear magnons and exchange Hamiltonians of delafossite proximate quantum spin liquids
• Synthesis and Anisotropic Magnetism in Quantum Spin Liquid Candidates $A$YbSe${}_2$ ($A$ = K and Rb)
• Anisotropic exchange coupling and ground state phase diagram of Kitaev compound YbOCl
• Low-energy Spin Dynamics of Quantum Spin Liquid Candidate $NaYbS{e}_2$
• Stripe-yz magnetic order in the triangular-lattice antiferromagnet KCeS2
• Rare-Earth Chalcogenides: An Inspiring Playground For Exploring Frustrated Magnetism
• Exchange renormalized crystal field excitation in a quantum Ising magnet KTmSe${}_2$
• Tracking the evolution from isolated dimers to many-body entanglement in NaLu${}_x$Yb${}_{1-x}$Se${}_2$
• Learning Effective Spin Hamiltonian of Quantum Magnet
• Role of alkaline metal in the rare-earth triangular antiferromagnet KYbO${}_2$
• Spin-wave dynamics in the KCeS2 delafossite: A theoretical description of powder inelastic neutron-scattering data
• Magnetism of $\mathrm{NaYb}{\mathrm{S}}_2$: From finite temperatures to ground state
• Thermodynamics and heat transport of quantum spin liquid candidates NaYbS${}_2$ and NaYbSe${}_2$
• Structural and magnetic characterization of CeTa${}_7$O${}_{19}$ and YbTa${}_7$O${}_{19}$ with two-dimensional pseudospin-1/2 triangular lattice
• Crystalline electric field excitations and their nonlinear splitting under magnetic fields in YbOCl
• Yb${}^{3+}$ $f$-$f$ excitations in NaYbSe${}_2$: benchmarking embedded-cluster quantum chemical schemes for 4$f$ insulators
• Effective Model for Rare-earth Kitaev Materials and its Classical Monte Carlo Simulation
• Finite Temperature Magnetism in the Triangular Lattice Antiferromagnet KErTe2
• Effects of the Crystalline Electric Field in the $KErT{e}_2$ Quantum Spin Liquid Candidate