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

Title: First-principles study of the magnetic interactions in honeycomb N a 2 Ir O 3

Abstract

Honeycomb iridate Na2IrO3, a Jeff=1/2 magnet, is a potential platform for realizing quantum spin liquid. Many experiments have shown that its magnetic ground state is a zigzag antiferromagnetic order. However, there is still a lack of consensus on the theoretical model explaining such order, since its second-nearest-neighbor (NN) and long-range third-NN magnetic interactions are highly unclear. By properly considering the orbital moments achieved through constraining their directions in first-principles calculations, we obtain that the relative angle between orbital and spin moments is fairly small and in the order of several degrees, which thus validates the Jeff=1/2 state in Na2IrO3. Surprisingly, we find that the long-range third-NN Heisenberg interactions are sizable, whereas the second-NN magnetic interactions are negligible. Furthermore, we show that sizable long-range third-NN Heisenberg interactions closely correlate with the appreciable distribution of Wannier orbitals of Jeff=1/2 states over the three NN Ir atoms. Based on our study, we propose a minimal J1-K1-G1-J3 model in which the magnetic excitations have an intensity peak at 5.6 meV, consistent with the inelastic neutron-scattering experiment [Phys. Rev. Lett. 108, 127204 (2012)10.1103/PhysRevLett.108.127204]. The present work demonstrates again that constraining orbital moments in first-principles calculations is a powerful way to investigate the intriguing magnetism inmore » Jeff=1/2 magnets, and it paves the way toward gaining a deep insight into the novel magnetism discovered in the honeycomb Jeff=1/2 magnets« less

Authors:
; ; ;
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
OSTI Identifier:
1475530
Report Number(s):
NREL/JA-5K00-72528
Journal ID: ISSN 2469-9950; PRBMDO
DOE Contract Number:  
AC36-08GO28308
Resource Type:
Journal Article
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 98; Journal Issue: 9; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; magnetism; iridates; density functional theory

Citation Formats

Hou, Y. S., Yang, J. H., Xiang, H. J., and Gong, X. G. First-principles study of the magnetic interactions in honeycomb Na2IrO3. United States: N. p., 2018. Web. doi:10.1103/PhysRevB.98.094401.
Hou, Y. S., Yang, J. H., Xiang, H. J., & Gong, X. G. First-principles study of the magnetic interactions in honeycomb Na2IrO3. United States. doi:10.1103/PhysRevB.98.094401.
Hou, Y. S., Yang, J. H., Xiang, H. J., and Gong, X. G. Sat . "First-principles study of the magnetic interactions in honeycomb Na2IrO3". United States. doi:10.1103/PhysRevB.98.094401.
@article{osti_1475530,
title = {First-principles study of the magnetic interactions in honeycomb Na2IrO3},
author = {Hou, Y. S. and Yang, J. H. and Xiang, H. J. and Gong, X. G.},
abstractNote = {Honeycomb iridate Na2IrO3, a Jeff=1/2 magnet, is a potential platform for realizing quantum spin liquid. Many experiments have shown that its magnetic ground state is a zigzag antiferromagnetic order. However, there is still a lack of consensus on the theoretical model explaining such order, since its second-nearest-neighbor (NN) and long-range third-NN magnetic interactions are highly unclear. By properly considering the orbital moments achieved through constraining their directions in first-principles calculations, we obtain that the relative angle between orbital and spin moments is fairly small and in the order of several degrees, which thus validates the Jeff=1/2 state in Na2IrO3. Surprisingly, we find that the long-range third-NN Heisenberg interactions are sizable, whereas the second-NN magnetic interactions are negligible. Furthermore, we show that sizable long-range third-NN Heisenberg interactions closely correlate with the appreciable distribution of Wannier orbitals of Jeff=1/2 states over the three NN Ir atoms. Based on our study, we propose a minimal J1-K1-G1-J3 model in which the magnetic excitations have an intensity peak at 5.6 meV, consistent with the inelastic neutron-scattering experiment [Phys. Rev. Lett. 108, 127204 (2012)10.1103/PhysRevLett.108.127204]. The present work demonstrates again that constraining orbital moments in first-principles calculations is a powerful way to investigate the intriguing magnetism in Jeff=1/2 magnets, and it paves the way toward gaining a deep insight into the novel magnetism discovered in the honeycomb Jeff=1/2 magnets},
doi = {10.1103/PhysRevB.98.094401},
journal = {Physical Review B},
issn = {2469-9950},
number = 9,
volume = 98,
place = {United States},
year = {2018},
month = {9}
}

Works referenced in this record:

Breakdown of magnons in a strongly spin-orbital coupled magnet
journal, October 2017


Zigzag Magnetic Order in the Iridium Oxide Na 2 IrO 3
journal, February 2013


Generalized Gradient Approximation Made Simple
journal, October 1996

  • Perdew, John P.; Burke, Kieron; Ernzerhof, Matthias
  • Physical Review Letters, Vol. 77, Issue 18, p. 3865-3868
  • DOI: 10.1103/PhysRevLett.77.3865

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


Ab initio analysis of the tight-binding parameters and magnetic interactions in Na 2 IrO 3
journal, July 2013


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


Projector augmented-wave method
journal, December 1994


Challenges in design of Kitaev materials: Magnetic interactions from competing energy scales
journal, June 2016


Novel J eff = 1 / 2 Mott State Induced by Relativistic Spin-Orbit Coupling in Sr 2 IrO 4
journal, August 2008


Mott physics and band topology in materials with strong spin–orbit interaction
journal, March 2010

  • Pesin, Dmytro; Balents, Leon
  • Nature Physics, Vol. 6, Issue 5
  • DOI: 10.1038/nphys1606

Na 2 IrO 3 as a Novel Relativistic Mott Insulator with a 340-meV Gap
journal, December 2012


Hyperhoneycomb Iridate β Li 2 IrO 3 as a Platform for Kitaev Magnetism
journal, February 2015


wannier90: A tool for obtaining maximally-localised Wannier functions
journal, May 2008

  • Mostofi, Arash A.; Yates, Jonathan R.; Lee, Young-Su
  • Computer Physics Communications, Vol. 178, Issue 9
  • DOI: 10.1016/j.cpc.2007.11.016

Spin Hamiltonian of hyper-kagome Na 4 Ir 3 O 8
journal, May 2010


Dynamical properties of the honeycomb-lattice iridates Na 2 IrO 3
journal, November 2015


Generic Spin Model for the Honeycomb Iridates beyond the Kitaev Limit
journal, February 2014


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


Relevance of the Heisenberg-Kitaev Model for the Honeycomb Lattice Iridates A 2 IrO 3
journal, March 2012


First-Principles Study of the Magnetic Structure of Na 2 IrO 3
journal, October 2015


Spin Waves and Revised Crystal Structure of Honeycomb Iridate Na 2 IrO 3
journal, March 2012


Maximally localized generalized Wannier functions for composite energy bands
journal, November 1997


Correlated electrons in high-temperature superconductors
journal, July 1994


Kitaev magnetism in honeycomb RuCl 3 with intermediate spin-orbit coupling
journal, June 2015


Fragile magnetic order in the honeycomb lattice Iridate Na 2 IrO 3 revealed by magnetic impurity doping
journal, October 2015


Importance of anisotropic exchange interactions in honeycomb iridates: Minimal model for zigzag antiferromagnetic order in Na 2 IrO 3
journal, October 2014


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


Kitaev-Heisenberg- J 2 - J 3 model for the iridates A 2 IrO 3
journal, November 2011


Density-functional theory and strong interactions: Orbital ordering in Mott-Hubbard insulators
journal, August 1995


Dynamical Properties of Quantum Many-Body Systems at Zero Temperature
journal, December 1987


Kitaev-Heisenberg models for iridates on the triangular, hyperkagome, kagome, fcc, and pyrochlore lattices
journal, January 2014


From a Quasimolecular Band Insulator to a Relativistic Mott Insulator in t 2 g 5 Systems with a Honeycomb Lattice Structure
journal, October 2016


Exchange Monte Carlo Method and Application to Spin Glass Simulations
journal, June 1996

  • Hukushima, Koji; Nemoto, Koji
  • Journal of the Physical Society of Japan, Vol. 65, Issue 6
  • DOI: 10.1143/JPSJ.65.1604

Strain-induced topological insulator phase and effective magnetic interactions in Li 2 IrO 3
journal, April 2013


Electron-Doped Sr 2 IrO 4 : An Analogue of Hole-Doped Cuprate Superconductors Demonstrated by Scanning Tunneling Microscopy
journal, November 2015


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


Predicting the spin-lattice order of frustrated systems from first principles
journal, December 2011


Monte Carlo Study of an Unconventional Superconducting Phase in Iridium Oxide J eff = 1 / 2 Mott Insulators Induced by Carrier Doping
journal, January 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

Long-range magnetic ordering in Na 2 IrO 3
journal, June 2011


Maximally localized Wannier functions for entangled energy bands
journal, December 2001


Topological semimetal and Fermi-arc surface states in the electronic structure of pyrochlore iridates
journal, May 2011


First-Principles Study of the Honeycomb-Lattice Iridates Na 2 IrO 3 in the Presence of Strong Spin-Orbit Interaction and Electron Correlations
journal, September 2014


Predicting a Ferrimagnetic Phase of Zn 2 FeOsO 6 with Strong Magnetoelectric Coupling
journal, April 2015