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Title: Concept and realization of Kitaev quantum spin liquids

Journal Article · · Nature Reviews Physics
ORCiD logo [1];  [2];  [2];  [3]; ORCiD logo [4]
  1. Max Planck Institute for Solid State Research, Stuttgart (Germany); Univ. of Stuttgart, Stuttgart (Germany); The Univ. of Tokyo, Tokyo (Japan)
  2. Max Planck Institute for Solid State Research, Stuttgart (Germany); Univ. of Stuttgart, Stuttgart (Germany)
  3. Max Planck Institute for Solid State Research, Stuttgart (Germany)
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

The Kitaev model is an exactly solvable S = 1/2 spin model on a 2D honeycomb lattice, in which the spins fractionalize into Majorana fermions and form a topological quantum spin liquid (QSL) in the ground state. Several complex iridium oxides, as well as α-RuCl3, are magnetic insulators with a honeycomb structure, and it was noticed that they accommodate essential ingredients of the Kitaev model owing to the interplay of electron correlation and spin–orbit coupling. This has led to a race to realize the Kitaev QSL and detect signatures of Majorana fermions. We summarize the theoretical background of the Kitaev QSL ground state and its realization using spin–orbital entangled Jeff = 1/2 moments. We provide an overview of candidate materials and their electronic and magnetic properties, including Na2IrO3, α-Li2IrO3, β-Li2IrO3, γ-Li2IrO3, α-RuCl3 and H3LiIr2O6. Lastly, we discuss experiments showing that H3LiIr2O6 and α-RuCl3 in an applied magnetic field exhibit signatures of the QSL state and that α-RuCl3 has unusual magnetic excitations and thermal transport properties consistent with spin fractionalization.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
AC05-00OR22725
OSTI ID:
1509555
Journal Information:
Nature Reviews Physics, Vol. 1, Issue 4; ISSN 2522-5820
Publisher:
Springer NatureCopyright Statement
Country of Publication:
United States
Language:
English

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Cited By (25)

Crystal structure and stacking faults in the layered honeycomb, delafossite-type materials Ag 3 LiIr 2 O 6 and Ag 3 LiRu 2 O 6 journal January 2019
Contrasted Sn substitution effects on Dirac line node semimetals SrIrO 3 and CaIrO 3 journal December 2019
Observation of spin-orbit excitations and Hund's multiplets in Ca 2 RuO 4 journal July 2019
Identification of emergent constraints and hidden order in frustrated magnets using tensorial kernel methods of machine learning journal November 2019
Counterrotating magnetic order in the honeycomb layers of NaNi 2 BiO 6 δ journal December 2019
Alleviating the sign problem in quantum Monte Carlo simulations of spin-orbit-coupled multiorbital Hubbard models journal January 2020
Anisotropic scattering continuum induced by crystal symmetry reduction in atomically thin α RuCl 3 journal January 2020
Impact of disorder on dynamics and ordering in the honeycomb-lattice iridate Na 2 IrO 3 journal February 2020
Hydrated lithium intercalation into the Kitaev spin liquid candidate material α − RuCl 3 journal June 2019
Electronic Properties of α RuCl 3 in Proximity to Graphene journal December 2019
Thermodynamic Evidence of Proximity to a Kitaev Spin Liquid in Ag 3 LiIr 2 O 6 journal December 2019
Nonequilibrium Majorana dynamics by quenching a magnetic field in Kitaev spin liquids journal October 2019
Valence bond fluctuations in the Kitaev spin model journal January 2020
Magnetic field induced competing phases in spin-orbital entangled Kitaev magnets journal January 2020
Unconventional magnetic field response of the hyperhoneycomb Kitaev magnet β Li 2 IrO 3 journal January 2020
Pressure-Tuned Interactions in Frustrated Magnets: Pathway to Quantum Spin Liquids? journal December 2019
Dynamical and thermal magnetic properties of the Kitaev spin liquid candidate α-RuCl3 journal January 2020
Resonant inelastic x-ray scattering study of $\alpha$ -RuCl 3 : a progress report journal January 2020
Crystal field splitting, local anisotropy, and low-energy excitations in the quantum magnet YbCl 3 journal November 2019
Random singlet state in Ba 5 CuIr 3 O 12 single crystals journal January 2020
Randomly Hopping Majorana Fermions in the Diluted Kitaev System α - Ru 0.8 Ir 0.2 Cl 3 journal January 2020
Polarization-resolved Raman spectroscopy of α RuCl 3 and evidence of room-temperature two-dimensional magnetic scattering journal October 2019
Nonequilibrium Majorana Dynamics by Quenching a Magnetic Field in Kitaev Spin Liquids text January 2019
Intrinsic sign problem in fermionic and bosonic chiral topological matter journal October 2020
Featureless quantum paramagnet with frustrated criticality and competing spiral magnetism on spin-1 honeycomb lattice magnet text January 2020

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