Bond ordering and phase transitions in Na${}_2$IrO${}_3$ under high pressure

Abstract

The Kitaev model of spin-1/2 on a honeycomb lattice supports degenerate topological ground states and may be useful in topological quantum computation. Na${}_2$IrO${}_3$ with honeycomb lattice of Ir ions have been extensively studied as candidates for the realization of the this model, due to the effective $J_{\text{eff}}=1/2$ low-energy excitations produced by spin-orbit and crystal-field effect. As the eventual realization of Kitaev model has remained evasive, it is highly desirable and challenging to tune the candidate materials toward such end. It is well known external pressure often leads to dramatic changes to the geometric and electronic structure of materials. In this work, the high pressure phase diagram of Na${}_2$IrO${}_3$ is examined by first-principles calculations. It is found that Na${}_2$IrO${}_3$ undergoes a sequence of structural and magnetic phase transitions, from the magnetically ordered phase with space group $C2/m$ to two bond-ordered non-magnetic phases. The low-energy excitations in these high-pressure phases can be well described by the $J_{\text{eff}}=1/2$ states.

arXiv comment5 pages,4 figures

References in corpus (22)

• 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
• 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
• Direct evidence of a zigzag spin chain structure in the honeycomb lattice: A neutron and x-ray diffraction investigation on single crystal $\mathrm{N}{\mathrm{a}}_2\mathrm{Ir}{\mathrm{O}}_3$
• Hyper-honeycomb iridate $\beta$-Li2IrO3 as a platform for Kitaev magnetism
• Evidence for a Field-induced Quantum Spin Liquid in $\alpha$-RuCl${}_3$
• Long range magnetic ordering in Na${}_2$IrO${}_3$
• A new spin-anisotropic harmonic honeycomb iridate
• Kitaev interactions between j=1/2 moments in honeycomb Na2IrO3 are large and ferromagnetic: insights from ab initio quantum chemistry calculations
• Gapless Spin Excitations in the Field-Induced Quantum Spin Liquid Phase of alpha-RuCl3
• First-Principles Study of the Honeycomb-Lattice Iridates Na2IrO3 in the Presence of Strong Spin-Orbit Interaction and Electron Correlations
• Incommensurate Counterrotating Magnetic Order Stabilized by Kitaev Interactions in the Layered Honeycomb $\alpha$-Li${}_2$IrO${}_3$
• Correlation-driven topological phase transition from in-plane magnetized quantum anomalous Hall to Mott insulating phase in monolayer transition metal trichlorides
• Pressure-induced dimerization and valence bond crystal formation in the Kitaev-Heisenberg magnet alpha-RuCl3
• Competition between spin-orbit coupling, magnetism, and dimerization in the honeycomb iridates: $\alpha$-Li${}_2$IrO${}_3$ under pressure
• ARPES study of the Kitaev Candidate $\alpha$-RuCl${}_3$
• Pressure-induced melting of magnetic order and emergence of new quantum state in alpha-RuCl3
• High-pressure magnetization and NMR studies on $\alpha$-RuCl${}_3$
• High-pressure versus isoelectronic doping effect on the honeycomb iridate Na${}_2$IrO${}_3$
• Computational Study of the Magnetic Structure of Na${}_2$IrO${}_3$

Cited by in corpus (9)

• Kitaev magnetism through the prism of lithium iridate
• Pressure-induced structural dimerization in the hyperhoneycomb iridate $\beta$-Li${}_2$IrO${}_3$ at low temperatures
• Complex pressure-temperature structural phase diagram of honeycomb iridate Cu${}_2$IrO${}_3$
• Optical signature of the pressure-induced dimerization in the honeycomb iridate $\alpha$-Li${}_2$IrO${}_3$
• Pressure tuning of structure, magnetic frustration and carrier conduction in Kitaev spin liquid candidate Cu${}_2$IrO${}_3$: X-ray, Raman, magnetic susceptibility, resistivity and first-principles analysis
• Quantum paramagnetism in the hyperhoneycomb Kitaev magnet $\beta$-ZnIrO${}_3$
• Lattice dynamics and structural transition of the hyperhoneycomb iridate $\beta$-Li${}_2$IrO${}_3$ investigated by high-pressure Raman scattering
• Competition between magnetic order and charge localization in Na${}_2$IrO${}_3$ thin crystal devices
• Honeycomb lattice iridate on the verge of Mott-collapse