Emergence of a nematic paramagnet via quantum order-by-disorder and pseudo-Goldstone modes in Kitaev magnets

Abstract

The appearance of nontrivial phases in Kitaev materials exposed to an external magnetic field has recently been a subject of intensive studies. Here, we elucidate the relation between the field-induced ground states of the classical and quantum spin models proposed for such materials, by using the infinite density matrix renormalization group (iDMRG) and the linear spin wave theory (LSWT). We consider the $K\Gamma {\Gamma }^{\prime }$ model, where $\Gamma$ and ${\Gamma }^{\prime }$ are off-diagonal spin exchanges on top of the dominant Kitaev interaction $K$. Focusing on the magnetic field along the $[111]$ direction, we explain the origin of the nematic paramagnet, which breaks the lattice-rotational symmetry and exists in an extended window of magnetic field, in the quantum model. This phenomenon can be understood as the effect of quantum order-by-disorder in the frustrated ferromagnet with a continuous manifold of degenerate ground states discovered in the corresponding classical model. We compute the dynamical spin structure factors using a matrix operator based time evolution and compare them with the predictions from LSWT. We, thus, provide predictions for future inelastic neutron scattering experiments on Kitaev materials in an external magnetic field along the $[111]$ direction. In particular, the nematic paramagnet exhibits a characteristic pseudo-Goldstone mode which results from the lifting of a continuous degeneracy via quantum fluctuations.

arXiv comment14 pages, 9 figure

References in corpus (56)

• 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
• Correlated quantum phenomena in the strong spin-orbit regime
• Majorana quantization and half-integer thermal quantum Hall effect in a Kitaev spin liquid
• Proximate Kitaev Quantum Spin Liquid Behaviour in α-RuCl${}_3$
• $\alpha$-RuCl3: a Spin-Orbit Assisted Mott Insulator on a Honeycomb Lattice
• Spin-Orbit Physics Giving Rise to Novel Phases in Correlated Systems: Iridates and Related Materials
• Neutron tomography of magnetic Majorana fermions in a proximate quantum spin liquid
• Generic spin model for the honeycomb iridates beyond the Kitaev limit
• Models and Materials for Generalized Kitaev Magnetism
• The monoclinic crystal structure of $\alpha$-RuCl${}_3$ and the zigzag antiferromagnetic ground state
• Magnetic order in $\alpha$-RuCl${}_3$: a honeycomb lattice quantum magnet with strong spin-orbit coupling
• Physics of the Kitaev model: fractionalization, dynamical correlations, and material connections
• Dynamics of a two-dimensional quantum spin liquid: signatures of emergent Majorana fermions and fluxes
• Excitations in the field-induced quantum spin liquid state of alpha-RuCl3
• Time-evolving a matrix product state with long-ranged interactions
• Nematic order in square lattice frustrated ferromagnets
• Hunting Majorana Fermions in Kitaev Magnets
• Crystal structure and magnetism in $\alpha$-RuCl3: an ab-initio study
• Anomalous thermal conductivity and magnetic torque response in the honeycomb magnet $\alpha$-RuCl${}_3$
• Large field-induced gap of Kitaev-Heisenberg paramagnons in $\alpha$-RuCl${}_3$
• Field-induced quantum criticality in the Kitaev system $\alpha$-RuCl${}_3$
• Spectral functions in one-dimensional quantum systems at T>0
• Magnetic Excitations and Continuum of a Field-Induced Quantum Spin Liquid in $\alpha$-RuCl${}_3$
• Magnetization processes of zigzag states on the honeycomb lattice: Identifying spin models for $\alpha$-RuCl${}_3$ and Na${}_2$IrO${}_3$
• Locality in Quantum and Markov Dynamics on Lattices and Networks
• Dynamics of Fractionalization in Quantum Spin Liquids
• Topological Magnons in Kitaev Magnets at High Fields
• Probing $\alpha$-RuCl${}_3$ Beyond Magnetic Order: Effects of Temperature and Magnetic Field
• Dynamics of the Kitaev-Heisenberg Model
• Spin-S Kitaev model: Classical Ground States, Order by Disorder and Exact Correlation Functions
• Ferromagnetic Kitaev interaction and the origin of large magnetic anisotropy in $\alpha$-RuCl${}_3$
• Quantum spin liquid signatures in Kitaev-like frustrated magnets
• Theory of the field-revealed Kitaev spin liquid
• Finite field regime for a quantum spin liquid in $\alpha$-RuCl${}_3$
• Dynamical and Topological Properties of the Kitaev Model in a [111] Magnetic Field
• Heisenberg-Kitaev physics in magnetic fields
• Topological excitations in the ferromagnetic Kitaev-Heisenberg model
• Clues and criteria for designing Kitaev spin liquid revealed by thermal and spin excitations of honeycomb iridates Na${}_2$IrO${}_3$
• Kitaev Materials
• Magnetic field induced quantum phases in a tensor network study of Kitaev magnets
• Infinite boundary conditions for matrix product state calculations
• One Proximate Kitaev Spin Liquid in the $K$-$J$-$\Gamma$ Model on the Honeycomb Lattice
• Unconventional spin dynamics in the honeycomb-lattice material $\alpha$-RuCl${}_3$: high-field ESR studies
• Classical spin liquid instability driven by off-diagonal exchange in strong spin-orbit magnets
• Pseudo-Goldstone gaps and order-by-quantum-disorder in frustrated magnets
• Magnetic Field Induced Competing Phases in Spin-Orbital Entangled Kitaev Magnets
• Classical and quantum spin dynamics of the honeycomb $\Gamma$ model
• Field-induced quantum spin liquid in the Kitaev-Heisenberg model and its relation to $\alpha$-RuCl${}_3$
• Phase diagram of the spin-1/2 Kitaev-Gamma chain and emergent SU(2) symmetry
• Kitaev honeycomb models in magnetic fields: Dynamical response and hidden symmetries
• Multinode quantum spin liquids on the honeycomb lattice
• Field-induced intermediate phase in $\alpha$-RuCl${}_3$: Non-coplanar order, phase diagram, and proximate spin liquid
• Ground-state properties of the $K-\Gamma$ model on a honeycomb lattice
• Symmetry-protected gapless spin liquids on the strained honeycomb lattice
• Large off diagonal exchange couplings and spin liquid states in ${\mathbf{C}}_3$ symmetric iridates

Cited by in corpus (34)

• Beyond Kitaev physics in strong spin-orbit coupled magnets
• Heisenberg-Kitaev model in a magnetic field: $1/S$ expansion
• Dynamics of visons and thermal Hall effect in perturbed Kitaev models
• The Heart of Entanglement: Chiral, Nematic, and Incommensurate Phases in the Kitaev-Gamma Ladder in a Field
• Gapless quantum spin liquid in a honeycomb $\Gamma$ magnet
• Functional renormalization group study of the Kitaev-$\Gamma$ model on the honeycomb lattice and emergent incommensurate magnetic correlations
• Revealing the Phase Diagram of Kitaev Materials by Machine Learning: Cooperation and Competition between Spin Liquids
• Easy-plane anisotropic-exchange magnets on a honeycomb lattice: quantum effects and dealing with them
• Machine-Learned Phase Diagrams of Generalized Kitaev Honeycomb Magnets
• Generic Field-Driven Phenomena in Kitaev Spin Liquids: Canted Magnetism and Proximate Spin Liquid Physics
• Extent of frustration in the classical Kitaev-$\Gamma$ model via bond anisotropy
• Spin-$S$ Kitaev-Heisenberg model on the honeycomb lattice: A high-order treatment via the many-body coupled cluster method
• Spin excitation continuum to topological magnon crossover and thermal Hall conductivity in Kitaev magnets
• Topological Nematic Phase Transition in Kitaev Magnets Under Applied Magnetic Fields
• Spontaneous Chiral-Spin Ordering in Spin-Orbit Coupled Honeycomb Magnets
• Microscopic Roadmap to a Yao-Lee Spin-Orbital Liquid
• Spontaneous dimerization, spin-nematic order, and deconfined quantum critical point in a spin-1 Kitaev chain with tunable single-ion anisotropy
• Magnon Condensation in Dimerized Antiferromagnets with Spin-Orbit Coupling
• Twice Hidden String Order and Competing Phases in the Spin-1/2 Kitaev-Gamma Ladder
• Topological phase diagrams of in-plane field polarized Kitaev magnets
• Extended Quantum Spin Liquid with Spinon-like Excitations in an Anisotropic Kitaev-Gamma Model
• Interplay of magnetic field and trigonal distortion in the honeycomb $\Gamma$ model: Occurrence of a spin-flop phase
• Topological phase transitions and thermal Hall effect in a noncollinear spin texture
• Kinetic Ferromagnetism and Topological Magnons of the Hole-Doped Kitaev Spin Liquid
• Chiral spin state and nematic ferromagnet in the spin-1 Kitaev-$\Gamma$ model
• Disentangling spin excitation continua in classical and quantum magnets using 2D nonlinear spectroscopy
• Successive topological phase transitions in two distinct spin-flop phases on the honeycomb lattice
• Interplay of Kitaev Interaction and Off-diagonal Exchanges: Exotic Phases and Quantum Phase Diagrams
• Field-Induced Ordered Phases in Anisotropic Spin-1/2 Kitaev Chains
• Complex orders and chirality in the classical Kitaev-$\Gamma$ model
• Ground-state phase diagram of anisotropically interacting Heisenberg-$\Gamma$ models on a honeycomb lattice
• Eleven Competing Phases in the Heisenberg-Gamma (J$\Gamma$) Ladder
• Field-induced phase transitions in the Kitaev-Heisenberg model: A sign-problem-free quantum Monte Carlo study and possible application to $\alpha$-RuCl3
• Anharmonic Collective Oscillations in Isotropic Spin Systems and their Spectroscopic Signatures