DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Breakdown of magnons in a strongly spin-orbital coupled magnet

Abstract

The description of quantized collective excitations stands as a landmark in the quantum theory of condensed matter. A prominent example occurs in conventional magnets, which support bosonic magnons - quantized harmonic fluctuations of the ordered spins. In striking contrast is the recent discovery that strongly spin-orbital coupled magnets, such as α-RuCl3, may display a broad excitation continuum inconsistent with conventional magnons. Due to incomplete knowledge of the underlying interactions unraveling the nature of this continuum remains challenging. The most discussed explanation refers to a coherent continuum of fractional excitations analogous to the celebrated Kitaev spin liquid. Here we present a more general scenario. We propose that the observed continuum represents incoherent excitations originating from strong magnetic anharmoniticity that naturally occurs in such materials. This scenario fully explains the observed inelastic magnetic response of α-RuCl3 and reveals the presence of nontrivial excitations in such materials extending well beyond the Kitaev state.

Authors:
ORCiD logo [1];  [1];  [2];  [2]; ORCiD logo [3];  [1]
  1. Goethe-Universität Frankfurt (Germany)
  2. Univ. of California, Irvine, CA (United States)
  3. Université de Cergy-Pontoise (France)
Publication Date:
Research Org.:
Univ. of California, Irvine, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
OSTI Identifier:
1499928
Alternate Identifier(s):
OSTI ID: 1784335
Grant/Contract Number:  
FG02-04ER46174
Resource Type:
Accepted Manuscript
Journal Name:
Nature Communications
Additional Journal Information:
Journal Volume: 8; Journal Issue: 1; Journal ID: ISSN 2041-1723
Publisher:
Nature Publishing Group
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Winter, Stephen M., Riedl, Kira, Maksimov, Pavel A., Chernyshev, Alexander L., Honecker, Andreas, and Valentí, Roser. Breakdown of magnons in a strongly spin-orbital coupled magnet. United States: N. p., 2017. Web. doi:10.1038/s41467-017-01177-0.
Winter, Stephen M., Riedl, Kira, Maksimov, Pavel A., Chernyshev, Alexander L., Honecker, Andreas, & Valentí, Roser. Breakdown of magnons in a strongly spin-orbital coupled magnet. United States. https://doi.org/10.1038/s41467-017-01177-0
Winter, Stephen M., Riedl, Kira, Maksimov, Pavel A., Chernyshev, Alexander L., Honecker, Andreas, and Valentí, Roser. Fri . "Breakdown of magnons in a strongly spin-orbital coupled magnet". United States. https://doi.org/10.1038/s41467-017-01177-0. https://www.osti.gov/servlets/purl/1499928.
@article{osti_1499928,
title = {Breakdown of magnons in a strongly spin-orbital coupled magnet},
author = {Winter, Stephen M. and Riedl, Kira and Maksimov, Pavel A. and Chernyshev, Alexander L. and Honecker, Andreas and Valentí, Roser},
abstractNote = {The description of quantized collective excitations stands as a landmark in the quantum theory of condensed matter. A prominent example occurs in conventional magnets, which support bosonic magnons - quantized harmonic fluctuations of the ordered spins. In striking contrast is the recent discovery that strongly spin-orbital coupled magnets, such as α-RuCl3, may display a broad excitation continuum inconsistent with conventional magnons. Due to incomplete knowledge of the underlying interactions unraveling the nature of this continuum remains challenging. The most discussed explanation refers to a coherent continuum of fractional excitations analogous to the celebrated Kitaev spin liquid. Here we present a more general scenario. We propose that the observed continuum represents incoherent excitations originating from strong magnetic anharmoniticity that naturally occurs in such materials. This scenario fully explains the observed inelastic magnetic response of α-RuCl3 and reveals the presence of nontrivial excitations in such materials extending well beyond the Kitaev state.},
doi = {10.1038/s41467-017-01177-0},
journal = {Nature Communications},
number = 1,
volume = 8,
place = {United States},
year = {2017},
month = {10}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 56 works
Citation information provided by
Web of Science

Figures / Tables:

Fig. 1 Fig. 1 : From material to model. Within the honeycomb ab-layer of $α$-RuCl3 are illustrated the RuCl6 octahedra, magnetic zigzag ordering pattern, and definition of the underlying magnetic interactions. Crystal axes are labeled with respect to the C2/m structure

Save / Share:

Works referenced in this record:

Scattering factors computed from relativistic Dirac–Slater wave functions
journal, January 1965


Proximate Kitaev quantum spin liquid behaviour in a honeycomb magnet
journal, April 2016

  • Banerjee, A.; Bridges, C. A.; Yan, J. -Q.
  • Nature Materials, Vol. 15, Issue 7
  • DOI: 10.1038/nmat4604

Spin liquids in frustrated magnets
journal, March 2010


Anyons in an exactly solved model and beyond
journal, January 2006


Dynamics of a Two-Dimensional Quantum Spin Liquid: Signatures of Emergent Majorana Fermions and Fluxes
journal, May 2014


Spin-Orbit Physics Giving Rise to Novel Phases in Correlated Systems: Iridates and Related Materials
journal, March 2016


Fermionic response from fractionalization in an insulating two-dimensional magnet
journal, July 2016

  • Nasu, J.; Knolle, J.; Kovrizhin, D. L.
  • Nature Physics, Vol. 12, Issue 10
  • DOI: 10.1038/nphys3809

Magnetic order in α RuCl 3 : A honeycomb-lattice quantum magnet with strong spin-orbit coupling
journal, April 2015


Theory of triplon dynamics in the quantum magnet BiCu 2 PO 6
journal, June 2016


Neutron scattering in the proximate quantum spin liquid α-RuCl 3
journal, June 2017


Two-Phonon Resonances and Hybridization of the Resonance with Single-Phonon States
journal, August 1970


Quantum phase transition in Heisenberg-Kitaev model
journal, December 2012


Kitaev interactions between j = 1/2 moments in honeycomb Na 2 IrO 3 are large and ferromagnetic: insights from ab initio quantum chemistry calculations
journal, January 2014


Field-induced decays in XXZ triangular-lattice antiferromagnets
journal, October 2016


Correlated electrons in high-temperature superconductors
journal, July 1994


Colloquium : Spontaneous magnon decays
journal, January 2013


Unified theory of spiral magnetism in the harmonic-honeycomb iridates α , β , and γ Li 2 IrO 3
journal, June 2015


Noncoplanar and Counterrotating Incommensurate Magnetic Order Stabilized by Kitaev Interactions in γ Li 2 IrO 3
journal, November 2014


Magnetic anisotropy in the Kitaev model systems Na 2 IrO 3 and RuCl 3
journal, August 2016


Scattering Continuum and Possible Fractionalized Excitations in α RuCl 3
journal, April 2015


Magnon Decay in Noncollinear Quantum Antiferromagnets
journal, November 2006


An iteration method for the solution of the eigenvalue problem of linear differential and integral operators
journal, October 1950

  • Lanczos, C.
  • Journal of Research of the National Bureau of Standards, Vol. 45, Issue 4
  • DOI: 10.6028/jres.045.026

Fractionalized excitations in the spin-liquid state of a kagome-lattice antiferromagnet
journal, December 2012

  • Han, Tian-Heng; Helton, Joel S.; Chu, Shaoyan
  • Nature, Vol. 492, Issue 7429
  • DOI: 10.1038/nature11659

Dynamical structure factor of the triangular-lattice antiferromagnet
journal, September 2013


Raman spectroscopic signature of fractionalized excitations in the harmonic-honeycomb iridates β- and γ-Li2IrO3
journal, July 2016

  • Glamazda, A.; Lemmens, P.; Do, S. -H.
  • Nature Communications, Vol. 7, Issue 1
  • DOI: 10.1038/ncomms12286

Experimental Realization of a 2D Fractional Quantum Spin Liquid
journal, February 2001


Linear spin wave theory for single-Q incommensurate magnetic structures
journal, March 2015


Dynamics of fractionalization in quantum spin liquids
journal, September 2015


Dynamics of an Antiferromagnet at Low Temperatures: Spin-Wave Damping and Hydrodynamics
journal, February 1971


Kitaev-Heisenberg Model on a Honeycomb Lattice: Possible Exotic Phases in Iridium Oxides A 2 IrO 3
journal, July 2010


Magnetic excitation spectrum of Na 2 IrO 3 probed with resonant inelastic x-ray scattering
journal, June 2013


Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
journal, January 2009


Direct evidence for dominant bond-directional interactions in a honeycomb lattice iridate Na2IrO3
journal, May 2015

  • Hwan Chun, Sae; Kim, Jong-Woo; Kim, Jungho
  • Nature Physics, Vol. 11, Issue 6
  • DOI: 10.1038/nphys3322

Hidden symmetries of the extended Kitaev-Heisenberg model: Implications for the honeycomb-lattice iridates A 2 IrO 3
journal, July 2015


Dynamics of the Kitaev-Heisenberg Model
journal, October 2017


Experimental Realization of a 2D Fractional Quantum Spin Liquid
text, January 2001


Works referencing / citing this record:

Dynamical and thermal magnetic properties of the Kitaev spin liquid candidate α-RuCl3
journal, January 2020


Concept and realization of Kitaev quantum spin liquids
journal, March 2019

  • Takagi, Hidenori; Takayama, Tomohiro; Jackeli, George
  • Nature Reviews Physics, Vol. 1, Issue 4
  • DOI: 10.1038/s42254-019-0038-2

Models and materials for generalized Kitaev magnetism
journal, November 2017

  • Winter, Stephen M.; Tsirlin, Alexander A.; Daghofer, Maria
  • Journal of Physics: Condensed Matter, Vol. 29, Issue 49
  • DOI: 10.1088/1361-648x/aa8cf5

Sub-gap optical response in the Kitaev spin-liquid candidate α -RuCl 3
journal, November 2018

  • Reschke, Stephan; Mayr, Franz; Widmann, Sebastian
  • Journal of Physics: Condensed Matter, Vol. 30, Issue 47
  • DOI: 10.1088/1361-648x/aae805

Heisenberg–Kitaev physics in magnetic fields
journal, July 2019


Frustration and quantum criticality
journal, May 2018


Deriving models for the Kitaev spin-liquid candidate material α RuCl 3 from first principles
journal, August 2019


Magnetic field-dependent low-energy magnon dynamics in α RuCl 3
journal, August 2019


Terahertz excitations in α RuC l 3 : Majorana fermions and rigid-plane shear and compression modes
journal, September 2019


Polarization-resolved Raman spectroscopy of α RuCl 3 and evidence of room-temperature two-dimensional magnetic scattering
journal, October 2019


Kitaev honeycomb models in magnetic fields: Dynamical response and dual models
journal, October 2019


Field-induced quantum spin liquid in the Kitaev-Heisenberg model and its relation to α RuCl 3
journal, October 2019


Unconventional spin dynamics in the honeycomb-lattice material α RuCl 3 : High-field electron spin resonance studies
journal, December 2017


Competition between spin-orbit coupling, magnetism, and dimerization in the honeycomb iridates: α Li 2 IrO 3 under pressure
journal, January 2018


Quantum spin liquid signatures in Kitaev-like frustrated magnets
journal, February 2018


Interlayer coupling effect on a bilayer Kitaev model
journal, March 2018


Role of spin-orbit coupling in the Kugel-Khomskii model on the honeycomb lattice
journal, March 2018


Effective model with strong Kitaev interactions for α RuCl 3
journal, April 2018


Dynamics of a quantum spin liquid beyond integrability: The Kitaev-Heisenberg- Γ model in an augmented parton mean-field theory
journal, April 2018

  • Knolle, Johannes; Bhattacharjee, Subhro; Moessner, Roderich
  • Physical Review B, Vol. 97, Issue 13
  • DOI: 10.1103/physrevb.97.134432

Classical and quantum spin dynamics of the honeycomb Γ model
journal, July 2018


Topological magnons in Kitaev magnets at high fields
journal, August 2018


Field-induced magnon excitation and in-gap absorption in the Kitaev candidate RuCl 3
journal, September 2018


Field evolution of magnons in α RuCl 3 by high-resolution polarized terahertz spectroscopy
journal, September 2018


Signatures of low-energy fractionalized excitations in α RuCl 3 from field-dependent microwave absorption
journal, November 2018


Kitaev-like honeycomb magnets: Global phase behavior and emergent effective models
journal, February 2019


Magnetic anisotropy of the alkali iridate Na 2 IrO 3 at high magnetic fields: Evidence for strong ferromagnetic Kitaev correlations
journal, February 2019


Antiferromagnetic Resonance and Terahertz Continuum in α RuCl 3
journal, November 2017


Magnetic Excitations and Continuum of a Possibly Field-Induced Quantum Spin Liquid in α RuCl 3
journal, November 2017


Ultralow-Temperature Thermal Conductivity of the Kitaev Honeycomb Magnet α RuCl 3 across the Field-Induced Phase Transition
journal, February 2018


Probing α RuCl 3 Beyond Magnetic Order: Effects of Temperature and Magnetic Field
journal, February 2018


Unusual Phonon Heat Transport in α RuCl 3 : Strong Spin-Phonon Scattering and Field-Induced Spin Gap
journal, March 2018


Unusual Thermal Hall Effect in a Kitaev Spin Liquid Candidate α RuCl 3
journal, May 2018


Sawtooth Torque in Anisotropic j eff = 1 / 2 Magnets: Application to α − RuCl 3
journal, May 2019


Hidden Plaquette Order in a Classical Spin Liquid Stabilized by Strong Off-Diagonal Exchange
journal, June 2019


Randomly Hopping Majorana Fermions in the Diluted Kitaev System α - Ru 0.8 Ir 0.2 Cl 3
journal, January 2020


Collective spin dynamics of Z 2 vortex crystals in triangular Kitaev-Heisenberg antiferromagnets
journal, August 2019


Nonequilibrium Majorana dynamics by quenching a magnetic field in Kitaev spin liquids
journal, October 2019


Unconventional magnetic field response of the hyperhoneycomb Kitaev magnet β Li 2 IrO 3
journal, January 2020


Neutron scattering in the proximate quantum spin liquid α-RuCl 3
journal, June 2017


Quantum spin liquids
journal, January 2020


Magnetic anisotropy of the alkali iridate Na2IrO3 at high magnetic fields: Evidence for strong ferromagnetic Kitaev correlations
text, January 2019

  • Das, Sd; Kundu, S.; Zhu, Z.
  • Apollo - University of Cambridge Repository
  • DOI: 10.17863/cam.37427

Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.