Large off diagonal exchange couplings and spin liquid states in ${\mathbf{C}}_3$ symmetric iridates

Abstract

Iridate oxides on a honeycomb lattice are considered promising candidates for realization of quantum spin liquid states. We investigate the magnetic couplings in a structural model for a honeycomb iridate K${}_2$IrO${}_3$, with $C_3$ point group symmetry at the Ir sites, which is an end member of the recently synthesized iridate family K${}_x$Ir${}_y$O${}_2$. Using \textit{ab-initio} quantum chemical methods, we elucidate the subtle relationship between the real space symmetry and magnetic anisotropy and show that the higher point group symmetry leads to high frustration with strong magnetic anisotropy driven by the unusually large off-diagonal exchange couplings ($\Gamma$'s) as opposed to other spin-liquid candidates considered so far. Consequently, large quantum fluctuations imply lack of magnetic ordering consistent with the experiments. Exact diagonalization calculations for the fully anisotropic $K$-$J$-$\Gamma$ Hamiltonian reveal the importance of the off-diagonal anisotropic exchange couplings in stabilizing a spin liquid state and highlight an alternative route to stabilize spin liquid states for ferromagnetic $K$.

arXiv comment8 pages, 3 figures, and Supplemental Material

References in corpus (34)

• Anyons in an exactly solved model and beyond
• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• Novel Jeff = 1/2 Mott State Induced by Relativistic Spin-Orbit Coupling in Sr2IrO4
• Kitaev-Heisenberg Model on Honeycomb Lattice: Possible Exotic Phases in Iridium Oxides $A_2$IrO${}_3$
• Proximate Kitaev Quantum Spin Liquid Behaviour in α-RuCl${}_3$
• $\alpha$-RuCl3: a Spin-Orbit Assisted Mott Insulator on a Honeycomb Lattice
• Relevance of the Heisenberg-Kitaev model for the honeycomb lattice iridates A_2IrO_3
• Generic spin model for the honeycomb iridates beyond the Kitaev limit
• Spin waves and revised crystal structure of honeycomb iridate Na2IrO3
• Challenges in Design of Kitaev Materials: Magnetic Interactions from Competing Energy Scales
• Excitations in the field-induced quantum spin liquid state of alpha-RuCl3
• Spin-orbit excitation energies, anisotropic exchange, and magnetic phases of honeycomb RuCl3
• 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
• Hidden symmetries of the extended Kitaev-Heisenberg model: Implications for honeycomb lattice iridates A2IrO3
• Kitaev-Heisenberg-J2-J3 model for the iridates A2IrO3
• Excitonic quasiparticles in a spin-orbit Mott insulator
• Quantum spin liquid signatures in Kitaev-like frustrated magnets
• Pressure-induced dimerization and valence bond crystal formation in the Kitaev-Heisenberg magnet alpha-RuCl3
• Anisotropic susceptibilities in the honeycomb Kitaev system $\alpha$-RuCl${}_3$
• Strongly frustrated triangular spin lattice emerging from triplet dimer formation in honeycomb Li2IrO3
• Classical spin liquid instability driven by off-diagonal exchange in strong spin-orbit magnets
• Orbital reconstruction in nonpolar tetravalent transition-metal oxide layers
• Tuning Magnetic Coupling in Sr${}_2$IrO${}_4$ Thin Films with Epitaxial Strain
• Breakdown of magnetic order in the pressurized Kitaev iridate $\beta$-Li${}_2$IrO${}_3$
• Origin of the insulating state in honeycomb iridates and rhodates
• Path to stable quantum spin liquids in spin-orbit coupled correlated materials
• Pressure-tuned magnetic interactions in honeycomb Kitaev materials
• Strong effect of hydrogen order on magnetic Kitaev interactions in H${}_3$LiIr${}_2$O${}_6$
• CaIrO3 post-perovskite, a j = 1/2 quasi-one-dimensional antiferromagnet
• The vicinity of hyper-honeycomb $\beta$-Li2IrO3 to a three-dimensional Kitaev spin liquid state
• Chemical- and hydrostatic-pressure effects on the Kitaev honeycomb material Na${}_2$IrO${}_3$
• Heavy-mass magnetic modes in pyrochlore iridates due to dominant Dzyaloshinskii-Moriya interaction
• Quantum Spin Liquid in a depleted triangular lattice Iridate K${}_x$Ir${}_y$O${}_2$

Cited by in corpus (6)

• Emergence of a nematic paramagnet via quantum order-by-disorder and pseudo-Goldstone modes in Kitaev magnets
• Competing Antiferromagnetic-Ferromagnetic States in $d^7$ Kitaev Honeycomb Magnet
• Revealing the Phase Diagram of Kitaev Materials by Machine Learning: Cooperation and Competition between Spin Liquids
• Machine-Learned Phase Diagrams of Generalized Kitaev Honeycomb Magnets
• Quantum phase transitions in the spin-1 Kitaev-Heisenberg chain
• Chemical tuning between triangular and honeycomb structures in a 5$d$ spin-orbit Mott insulator