Relevance of the Heisenberg-Kitaev Model for the Honeycomb Lattice Iridates A2IrO3

Yogesh Singh, S. Manni, J. Reuther, T. Berlijn, R. Thomale, W. Ku, S. Trebst, and P. Gegenwart
Phys. Rev. Lett. 108, 127203 – Published 20 March 2012
PDFHTMLExport Citation

Abstract

Combining thermodynamic measurements with theoretical calculations we demonstrate that the iridates A2IrO3 (A=Na, Li) are magnetically ordered Mott insulators where the magnetism of the effective spin-orbital S=1/2 moments can be captured by a Heisenberg-Kitaev (HK) model with interactions beyond nearest-neighbor exchange. Experimentally, we observe an increase of the Curie-Weiss temperature from θ125K for Na2IrO3 to θ33K for Li2IrO3, while the ordering temperature remains roughly the same TN15K. Using functional renormalization group calculations we show that this evolution of θ and TN as well as the low temperature zigzag magnetic order can be captured within this extended HK model. We estimate that Na2IrO3 is deep in a magnetically ordered regime, while Li2IrO3 appears to be close to a spin-liquid regime.

  • Figure
  • Figure
  • Figure
  • Received 2 June 2011

DOI:https://doi.org/10.1103/PhysRevLett.108.127203

© 2012 American Physical Society

Authors & Affiliations

Yogesh Singh1,2, S. Manni2, J. Reuther3,4, T. Berlijn5,6, R. Thomale7, W. Ku5,6, S. Trebst8, and P. Gegenwart2

  • 1Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Manauli PO 140306, India
  • 2I. Physikalisches Institut, Georg-August-Universität Göttingen, D-37077, Göttingen, Germany
  • 3Institut für Theorie der Kondensierten Materie, Karlsruhe Institute of Technology, D-76128 Karlsruhe, Germany
  • 4Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
  • 5Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
  • 6Physics Department, State University of New York, Stony Brook, New York 11790, USA
  • 7Department of Physics, Stanford University, Stanford, California 94305, USA
  • 8Institute for Theoretical Physics, University of Cologne, 50937 Cologne, Germany

See Also

Spin Waves and Revised Crystal Structure of Honeycomb Iridate Na2IrO3

S. K. Choi, R. Coldea, A. N. Kolmogorov, T. Lancaster, I. I. Mazin, S. J. Blundell, P. G. Radaelli, Yogesh Singh, P. Gegenwart, K. R. Choi, S.-W. Cheong, P. J. Baker, C. Stock, and J. Taylor
Phys. Rev. Lett. 108, 127204 (2012)

Article Text (Subscription Required)

Click to Expand

Supplemental Material (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 108, Iss. 12 — 23 March 2012

Reuse & Permissions
Access Options
CHORUS

Article Available via CHORUS

Download Accepted Manuscript
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review Letters

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×