skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Spin dynamics and field-induced magnetic phase transition in the honeycomb Kitaev magnet α Li 2 IrO 3

Journal Article · · Physical Review B
 [1];  [2];  [3];  [4];  [5];  [6];  [7];  [3];  [8];  [6]
  1. Univ. of Oxford Physics Dept., Oxford (United Kingdom). Clarendon Lab.; Rutgers Univ., Piscataway, NJ (United States). Rutgers Center for Emergent Materials and Dept. of Physics and Astronomy
  2. Augsburg Univ., Augsburg (Germany). EP VI, Center for Electronic Correlations and Magnetism; Indian Inst. of Technology Palakkad, Kerala (India)
  3. Los Alamos National Lab. (LANL), Los Alamos, NM (United States). National High Magnetic Field Lab.
  4. Univ. of Oxford Physics Dept., Oxford (United Kingdom). Clarendon Lab.; Los Alamos National Lab. (LANL), Los Alamos, NM (United States). National High Magnetic Field Lab.
  5. Durham Univ., Durham (United Kingdom). Dept. of Physics
  6. Univ. of Oxford Physics Dept., Oxford (United Kingdom). Clarendon Lab.
  7. Rutherford Appleton Lab-STFC, Chilton, Didcot (United Kingdom). ISIS Facility; Univ. of Johannesburg, Auckland Park (South Africa). Highly Correlated Matter Research Group, Physics Dept.
  8. Augsburg Univ., Augsburg (Germany). EP VI, Center for Electronic Correlations and Magnetism

The layered honeycomb iridate $$α-Li_2IrO_3$$ displays an incommensurate magnetic structure with counter-rotating moments on nearest-neighbor sites, proposed to be stabilized by strongly frustrated anisotropic Kitaev interactions between spin-orbit entangled $$Ir^{4+}$$ magnetic moments. Here we report powder inelastic neutron scattering measurements that observe sharply dispersive low-energy magnetic excitations centered at the magnetic ordering wave vector, attributed to Goldstone excitations of the incommensurate order, as well as an additional intense mode above a gap $Δ ≃ 2.3$ meV. Zero-field muon-spin relaxation measurements show clear oscillations in the muon polarization below the Néel temperature $$T_N ≃ 15$$ K with a time-dependent profile consistent with bulk incommensurate long-range magnetism. Pulsed-field magnetization measurements observe that only about half the saturation magnetization value is reached at the maximum field of 64 T. A clear anomaly near 25 T indicates a transition to a phase with reduced susceptibility. The transition field has a Zeeman energy comparable to the zero-field gapped mode, suggesting gap suppression as a possible mechanism for the field-induced transition.

Research Organization:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Organization:
USDOE
Grant/Contract Number:
89233218CNA000001
OSTI ID:
1565889
Alternate ID(s):
OSTI ID: 1546160
Report Number(s):
LA-UR-18-29558; PRBMDO; TRN: US2000930
Journal Information:
Physical Review B, Vol. 99, Issue 5; ISSN 2469-9950
Publisher:
American Physical Society (APS)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 20 works
Citation information provided by
Web of Science

References (55)

Dynamics of a Two-Dimensional Quantum Spin Liquid: Signatures of Emergent Majorana Fermions and Fluxes journal May 2014
Incommensurate counterrotating magnetic order stabilized by Kitaev interactions in the layered honeycomb α Li 2 IrO 3 journal May 2016
Pressure tuning of bond-directional exchange interactions and magnetic frustration in the hyperhoneycomb iridate β Li 2 IrO 3 journal October 2017
Single crystal growth from separated educts and its application to lithium transition-metal oxides journal October 2016
Challenges in design of Kitaev materials: Magnetic interactions from competing energy scales journal June 2016
Excitations in the field-induced quantum spin liquid state of α-RuCl3 journal February 2018
Phase diagram of α RuCl 3 in an in-plane magnetic field journal May 2017
Magnetic structure and excitation spectrum of the hyperhoneycomb Kitaev magnet β Li 2 IrO 3 journal March 2018
Unconventional magnetic order on the hyperhoneycomb Kitaev lattice in β Li 2 IrO 3 : Full solution via magnetic resonant x-ray diffraction journal November 2014
Robust spin correlations at high magnetic fields in the harmonic honeycomb iridates journal August 2017
Electron correlation in the two-dimensional triangle lattice of Na x CoO 2 journal June 2004
Probing α RuCl 3 Beyond Magnetic Order: Effects of Temperature and Magnetic Field journal February 2018
Spin dynamics of counterrotating Kitaev spirals via duality journal November 2016
Unified theory of spiral magnetism in the harmonic-honeycomb iridates α , β , and γ Li 2 IrO 3 journal June 2015
Theory of magnetic phase diagrams in hyperhoneycomb and harmonic-honeycomb iridates journal February 2015
Noncoplanar and Counterrotating Incommensurate Magnetic Order Stabilized by Kitaev Interactions in γ Li 2 IrO 3 journal November 2014
Breakdown of Magnetic Order in the Pressurized Kitaev Iridate β Li 2 IrO 3 journal June 2018
α RuCl 3 : A spin-orbit assisted Mott insulator on a honeycomb lattice journal July 2014
A spin–orbital-entangled quantum liquid on a honeycomb lattice journal February 2018
The National High Magnetic Field Laboratory journal November 2006
Realization of a three-dimensional spin–anisotropic harmonic honeycomb iridate journal June 2014
Spin dynamics and field-induced magnetic phase transition in the honeycomb Kitaev magnet alpha-Li2IrO3 dataset January 2019
Zigzag Magnetic Order in the Iridium Oxide Na 2 IrO 3 journal February 2013
Proximate Kitaev quantum spin liquid behaviour in a honeycomb magnet journal April 2016
Anyons in an exactly solved model and beyond journal January 2006
Monoclinic crystal structure of α RuCl 3 and the zigzag antiferromagnetic ground state journal December 2015
Spin-Orbit Physics Giving Rise to Novel Phases in Correlated Systems: Iridates and Related Materials journal March 2016
Covalency Effects in the Magnetic Form Factor of Ir in K 2 Ir Cl 6 journal July 1976
Experimentally determining the exchange parameters of quasi-two-dimensional Heisenberg magnets journal August 2008
Physics of the Kitaev Model: Fractionalization, Dynamic Correlations, and Material Connections journal March 2018
Neutron scattering in the proximate quantum spin liquid α-RuCl 3 journal June 2017
Hyperhoneycomb Iridate β Li 2 IrO 3 as a Platform for Kitaev Magnetism journal February 2015
Majorana quantization and half-integer thermal quantum Hall effect in a Kitaev spin liquid journal July 2018
Spin-polarized muons in condensed matter physics journal May 1999
Relevance of the Heisenberg-Kitaev Model for the Honeycomb Lattice Iridates A 2 IrO 3 journal March 2012
Spin Waves and Revised Crystal Structure of Honeycomb Iridate Na 2 IrO 3 journal March 2012
Majorana fermions in the Kitaev quantum spin system α-RuCl3 journal September 2017
Magnetization Process of a Screw Spin System journal June 1962
Direct evidence of a zigzag spin-chain structure in the honeycomb lattice: A neutron and x-ray diffraction investigation of single-crystal Na 2 IrO 3 journal May 2012
Antiferromagnetic Mott insulating state in single crystals of the honeycomb lattice material Na 2 IrO 3 journal August 2010
Two iridates, two models, and two approaches: A comparative study on magnetism in three-dimensional honeycomb materials journal May 2016
Correlated states in β-Li2IrO3 driven by applied magnetic fields journal October 2017
Magnetic excitation spectrum of Na 2 IrO 3 probed with resonant inelastic x-ray scattering journal June 2013
Magnetic field induced evolution of intertwined orders in the Kitaev magnet β Li 2 IrO 3 journal May 2018
Direct evidence for dominant bond-directional interactions in a honeycomb lattice iridate Na2IrO3 journal May 2015
Long-range magnetic ordering in Na 2 IrO 3 journal June 2011
Excitations in the field-induced quantum spin liquid state of α-RuCl3 text January 2018
Magnetic anisotropy of the alkali iridate Na2IrO3 at high magnetic fields: Evidence for strong ferromagnetic Kitaev correlations text January 2019
Neutron scattering in the proximate quantum spin liquid α-RuCl3. text January 2017
Physics of the Kitaev model: fractionalization, dynamical correlations, and material connections text January 2018
Theory of Magnetic Phase Diagrams in Hyperhoneycomb and Harmonic-honeycomb Iridates text January 2014
Spin-Orbit Physics Giving Rise to Novel Phases in Correlated Systems: Iridates and Related Materials text January 2015
Challenges in Design of Kitaev Materials: Magnetic Interactions from Competing Energy Scales text January 2016
Spin dynamics of counterrotating Kitaev spirals via duality text January 2016
Anyons in an exactly solved model and beyond text January 2005

Cited By (4)