Unusual spin dynamics in the low-temperature magnetically ordered state of Ag${}_3$LiIr${}_2$O${}_6$

Abstract

Recently, there have been contrary claims of Kitaev spin-liquid behaviour and ordered behavior in the honeycomb compound Ag${}_3$LiIr${}_2$O${}_6$ based on various experimental signatures. Our investigations on this system reveal a low-temperature ordered state with persistent dynamics down to the lowest temperatures. Magnetic order is confirmed by clear oscillations in the muon spin relaxation ($\mu$SR) time spectrum below 9 K till 52 mK. Coincidentally in ${}^7$Li nuclear magnetic resonance, a wipe-out of the signal is observed below $\sim$ 10 K which again strongly indicates magnetic order in the low temperature regime. This is supported by our density functional theory calculations which show an appreciable Heisenberg exchange term in the spin Hamiltonian that favors magnetic ordering. The ${}^7$Li shift and spin-lattice relaxation rate also show anomalies at $\sim$ 50 K. They are likely related to the onset of dynamic magnetic correlations, but their origin is not completely clear. Detailed analysis of our $\mu$SR data is consistent with a co-existence of incommensurate Néel and striped environments. A significant and undiminished dynamical relaxation rate ($\sim 5$ MHz) as seen in $\mu$SR deep into the ordered phase indicates enhanced quantum fluctuations in the ordered state.

arXiv comment11 pages, 10 figures

References in corpus (31)

• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• Kitaev-Heisenberg Model on Honeycomb Lattice: Possible Exotic Phases in Iridium Oxides $A_2$IrO${}_3$
• Generic spin model for the honeycomb iridates beyond the Kitaev limit
• Spin waves and revised crystal structure of honeycomb iridate Na2IrO3
• On the Origin of Zigzag Magnetic Order in Iridium Oxide Na2IrO3
• Challenges in Design of Kitaev Materials: Magnetic Interactions from Competing Energy Scales
• Muffin Tin Orbitals of Arbitrary Order
• Spin-polarized muons in condensed matter physics
• Excitonic Magnetism in Van Vleck-type d^4 Mott Insulators
• Crystal field splitting and correlation effect on the electronic structure of A2IrO3
• Kitaev interactions between j=1/2 moments in honeycomb Na2IrO3 are large and ferromagnetic: insights from ab initio quantum chemistry calculations
• Incommensurate Counterrotating Magnetic Order Stabilized by Kitaev Interactions in the Layered Honeycomb $\alpha$-Li${}_2$IrO${}_3$
• Thermodynamic Evidence of Proximity to a Kitaev Spin-Liquid in Ag${}_3$LiIr${}_2$O${}_6$
• Unveiling Magnetic Interactions of Ruthenium Trichloride via Constraining Direction of Orbital moments: Potential Routes to Realize Quantum Spin Liquid
• Origin of the insulating state in honeycomb iridates and rhodates
• Effect of isoelectronic doping on honeycomb lattice iridate A_2IrO_3
• Strong effect of hydrogen order on magnetic Kitaev interactions in H${}_3$LiIr${}_2$O${}_6$
• Role of Hydrogen in the spin-orbital-entangled quantum liquid candidate H${}_3$LiIr${}_2$O${}_6$
• The vicinity of hyper-honeycomb $\beta$-Li2IrO3 to a three-dimensional Kitaev spin liquid state
• Gapless quantum spin liquid in the triangular system Sr${}_3$CuSb${}_2$O${}_9$
• Signatures of a spin-1/2 cooperative paramagnet in the diluted triangular lattice of Y${}_2$CuTiO${}_6$
• Effect of structural disorder on the Kitaev magnet Ag${}_3$LiIr${}_2$O${}_6$
• Novel magnetism on a honeycomb lattice in a-RuCl3 studied by muon spin rotation
• Unconventional magnetism in the 4d${}^4$ based ($S=1$) honeycomb system Ag${}_3$LiRu${}_2$O${}_6$
• NMR Investigation on Honeycomb Iridate Ag${}_3$LiIr${}_2$O${}_6$
• Structural, thermodynamic, and local probe investigations of a honeycomb material Ag${}_3$LiMn${}_2$O${}_6$
• First-principles Study on the Magnetic Interactions in Honeycomb Na2IrO3
• Local spin structure of the $\alpha$-RuCl${}_3$ honeycomb-lattice magnet observed via muon spin rotation/relaxation
• Pressure-induced formation of rhodium zigzag chains in the honeycomb rhodate Li${}_2$RhO${}_3$
• Muon-spin relaxation study of the double perovskite insulators Sr${}_{2}B$OsO${}_6$ ($B=\mathrm{Fe},\mathrm{Y},\mathrm{In}$)
• Kitaev quasiparticles in a proximate spin liquid: A many-body localization perspective

Cited by in corpus (8)

• Beyond Kitaev physics in strong spin-orbit coupled magnets
• Experimental signatures of quantum and topological states in frustrated magnetism
• Kitaev magnetism through the prism of lithium iridate
• Nearly itinerant electronic groundstate in the intercalated honeycomb iridate Ag${}_3$LiIr${}_2$O${}_6$
• Magnetic properties of a spin-orbit entangled Jeff = 1/2 honeycomb lattice
• Raman fingerprints of fractionalized Majorana excitations in honeycomb iridate Ag${}_3$LiIr${}_2$O${}_6$
• (H,Li)${}_6$Ru${}_2$O${}_6$ : a possible zero-field Ru${}^{3+}$-based Kitaev Quantum Spin Liquid
• Susceptibility anisotropy and absence of ferroelectric order in the Kitaev spin liquid candidate Na${}_2$Co${}_2$TeO${}_6$