(H,Li)${}_6$Ru${}_2$O${}_6$ : a possible zero-field Ru${}^{3+}$-based Kitaev Quantum Spin Liquid

Abstract

We report the synthesis and properties of (H,Li)${}_6$Ru${}_2$O${}_6$, which is shown to be a $J_{\text{eff}}=\frac{1}{2}$ system made out of Ru${}^{3+}$ moments in a honeycomb geometry. Bulk magnetization, heat capacity, nuclear magnetic resonance (NMR), and muon spin relaxation ($\mu$SR) rule out the presence of static moments or any spin glass phase down to 84 mK. All techniques suggest a crossover to a liquid-like state below about 40 K. The ${}^7$Li nuclear magnetic resonance (NMR) shift data suggest a non-zero $T$-independent spin susceptibility at low $T$. In zero field, $C_m/T$ shows $T^{-0.9}$ divergence which is consistent with vacancy-induced effects on low-energy excitations of the pristine Kitaev spin liquid. With field, power-law variations in the ${}^7$Li NMR spin-lattice relaxation rate 1/T${}_1$ and magnetic heat capacity $C_m$ show quantitatively new scaling behaviors. A two-step entropy release in heat capacity is also observed putatively from $Z_2$ flux (low-$T$ step) and itinerant Majorana fermions (high-$T$ step). Based on these findings, we propose that (H,Li)${}_6$Ru${}_2$O${}_6$ realizes a Kitaev spin liquid with no evidence of inherent magnetic ordering in zero field unlike $\alpha$-RuCl${}_3$ where approximately $8$ Tesla field is required to suppress magnetic order.

This is closest to the published version of 5 pages, 6 figures of main text + 12 pages, and 29 figures of supplementary information

References in corpus (29)

• Anyons in an exactly solved model and beyond
• Novel Jeff = 1/2 Mott State Induced by Relativistic Spin-Orbit Coupling in Sr2IrO4
• Kitaev quantum spin liquid - concept and materialization
• Neutron tomography of magnetic Majorana fermions in a proximate quantum spin liquid
• Evidence for a Field-induced Quantum Spin Liquid in $\alpha$-RuCl${}_3$
• Excitonic Magnetism in Van Vleck-type d^4 Mott Insulators
• Hunting Majorana Fermions in Kitaev Magnets
• Thermal fractionalization of quantum spins in a Kitaev model: $T$-linear specific heat and coherent transport of Majorana fermions
• $\mu$SR evidence for the U(1) quantum spin liquid ground state in the triangular antiferromagnet YbMgGaO${}_4$
• Anisotropic Ru3+ 4d5 magnetism in the alpha-RuCl3 honeycomb system: susceptibility, specific heat and Zero field NMR
• Incommensurate Counterrotating Magnetic Order Stabilized by Kitaev Interactions in the Layered Honeycomb $\alpha$-Li${}_2$IrO${}_3$
• Emergence of a Field-Driven U(1) Spin Liquid in the Kitaev Honeycomb Model
• New Type Phase Transition of Li2RuO3 with Honeycomb Structure
• Clues and criteria for designing Kitaev spin liquid revealed by thermal and spin excitations of honeycomb iridates Na${}_2$IrO${}_3$
• Thermodynamic Evidence of Proximity to a Kitaev Spin-Liquid in Ag${}_3$LiIr${}_2$O${}_6$
• Path to stable quantum spin liquids in spin-orbit coupled correlated materials
• Vacancy-induced low-energy density of states in the Kitaev spin liquid
• Spin-orbit-controlled metal-insulator transition in Sr${}_2$IrO${}_4$
• 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${}_6$
• Magnetic Raman continuum in single crystalline H${}_3$LiIr${}_2$O${}_6$
• Universal Thermodynamics in the Kitaev Fractional Liquid
• Nontrivial Triplon Topology and Triplon Liquid in Kitaev-Heisenberg-type Excitonic Magnets
• Highly frustrated magnetism in relativistic ${\mathbf{d}}^4$ Mott insulators: Bosonic analog of Kitaev honeycomb model
• A $j_{\mathrm{eff}}=1/2$ Kitaev material on the triangular lattice: The case of NaRuO${}_2$
• Unconventional magnetism in the 4d${}^4$ based ($S=1$) honeycomb system Ag${}_3$LiRu${}_2$O${}_6$
• Unusual spin dynamics in the low-temperature magnetically ordered state of Ag${}_3$LiIr${}_2$O${}_6$
• Competing spin-orbital singlet states in the 4$d^4$ honeycomb ruthenate Ag${}_3$LiRu${}_2$O${}_6$
• NaRuO${}_2$: Kitaev-Heisenberg exchange in triangular-lattice setting

Cited by in corpus (2)

• Spiral spin liquid resilient to quantization in the frustrated honeycomb antiferromagnet GdZnPO
• Susceptibility anisotropy and absence of ferroelectric order in the Kitaev spin liquid candidate Na${}_2$Co${}_2$TeO${}_6$