The nature of low-temperature spin-freezing in frustrated Kitaev magnets

Abstract

The subtle interplay between competing degrees of freedom, anisotropy, and spin correlations in frustrated Kitaev quantum materials offers an ideal platform to host non-trivial quantum states with exotic fractional excitations. The signature of spin-freezing behavior of these spin-orbit-driven frustrated magnets is characterized by a bifurcation of zero-field-cooled and field-cooled magnetic susceptibility at low temperatures much below the characteristic interaction energy scale of spins. The temperature dependence of magnetic specific heat exhibits Cm~ T^2 dependence near the freezing temperature. The field-independent behavior of Cm below the freezing temperature implies the presence of exotic low-energy excitations. The aging and memory effect experiments in the Kitaev magnets suggest a non-hierarchical free energy distribution, which differs from the hierarchical organization of conventional spin-freezing. Furthermore, the NMR spin-lattice relaxation rate follows a power law behavior below the spin-freezing temperature, suggesting the persistence of unconventional spin excitation spectra. Herein, we demonstrate that the observed low-temperature spin-freezing phenomena in a few representative Kitaev quantum materials can be effectively explained by the Halperin and Saslow (HS) hydrodynamic modes relevant for non-trivial spin glass materials. The linearly dispersive HS modes are hypothesized to account for instigating non-abelian defect propagation, thereby inducing a spin jam state in the low-temperature regime in frustrated Kitaev magnets. Our investigation reveals that HS modes capture the essence of unconventional spin-freezing ascribed to topological origin in two-dimensional (2D) Kitaev magnets decorated on a honeycomb lattice and its 3D analog hyperhoneycomb that offers a viable ground to extend this framework to a large class of frustrated quantum materials.

References in corpus (35)

• Many body localization and thermalization in quantum statistical mechanics
• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• Quantum Many-Body Scars and Weak Breaking of Ergodicity
• On the Origin of Zigzag Magnetic Order in Iridium Oxide Na2IrO3
• Magnetic order in $\alpha$-RuCl${}_3$: a honeycomb lattice quantum magnet with strong spin-orbit coupling
• Hyper-honeycomb iridate $\beta$-Li2IrO3 as a platform for Kitaev magnetism
• Long range magnetic ordering in Na${}_2$IrO${}_3$
• Order by disorder and spiral spin liquid in frustrated diamond lattice antiferromagnets
• Non-coplanar and counter-rotating incommensurate magnetic order stabilized by Kitaev interactions in $\gamma$-Li2IrO3
• Spin-S Kitaev model: Classical Ground States, Order by Disorder and Exact Correlation Functions
• Quadrupolar correlations and spin freezing in S = 1 triangular lattice antiferromagnets
• Unified theory of spiral magnetism in the harmonic-honeycomb iridates α, β, γ Li2IrO3
• Spin dynamics and spin freezing behavior in the two-dimensional antiferromagnet NiGa${}_2$S${}_4$ revealed by Ga-NMR, NQR and $\mu$SR measurements
• Evidence of the Berezinskii-Kosterlitz-Thouless Phase in a Frustrated Magnet
• Excitations in the ordered and paramagnetic states of honeycomb magnet Na2Co2TeO6
• Effect of nonmagnetic dilution in honeycomb lattice iridates Na${}_2$IrO${}_3$ and Li${}_2$IrO${}_3$
• Experimental signatures of quantum and topological states in frustrated magnetism
• Magnetic field induced quantum spin liquid in the two coupled trillium lattices of K${}_2$Ni${}_2$(SO${}_4$)${}_3$
• Aging, memory, and nonhierarchical energy landscape of spin jam
• Vortex-induced topological transition of the bilinear-biquadratic Heisenberg antiferromagnet on the triangular lattice
• Intrinsic susceptibility and bond defects in the novel 2D frustrated antiferromagnet Ba${}_2$Sn${}_2$ZnCr${}_{7p}$Ga${}_{10-7p}$O${}_{22}$
• High Field ESR in the Two-Dimensional Triangular Lattice Antiferromagnet NiGa2S4
• Spin-glass state and reversed magnetic anisotropy induced by Cr doping in the Kitaev magnet $\alpha$-RuCl${}_3$
• Halperin-Saslow modes as the origin of the low temperature anomaly in $NiG{a}_2{S}_4$
• Eminuscent phase in frustrated magnets: a challenge to quantum spin liquids
• Robust quantum many-body scars in the one-dimensional spin-1 Kitaev model
• Emergent glassiness in disorder-free Kitaev model: Density matrix renormalization group study on a one-dimensional ladder setting
• Freezing of a disorder induced quantum spin liquid
• First demonstration of tuning between the Kitaev and Ising limits in a honeycomb lattice
• Quantum paramagnetism in the hyperhoneycomb Kitaev magnet $\beta$-ZnIrO${}_3$
• $Z_2$ flux binding to higher-spin impurities in the Kitaev spin liquid
• Quantum-classical crossover in the spin-1/2 Heisenberg-Kitaev kagome magnet
• Emergent Halperin-Saslow mode and Gauge Glass in quantum Ising magnet TmMgGaO${}_4$
• Monoclinic distortion in hyperhoneycomb Kitaev material $\beta$-ZnIrO${}_3$ revealed by improved sample quality
• Zero-point entropies of spin-jam and spin-glass states in a frustrated magnet

Cited by in corpus (2)

• Magnetic ground state of a Jeff = 1/2 based frustrated triangular lattice antiferromagnet
• Electronic and magnetic ground state of 4$d^3$ double perovskite ruthenates A${}_2$LaRuO${}_6$ (A $=$ Ca, Sr, Ba)