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Plaquette valence bond ordering in a J1-J2 Heisenberg antiferromagnet on a honeycomb lattice

Mosadeq, H ; Sharif University of Technology

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  1. Type of Document: Article
  2. DOI: 10.1088/0953-8984/23/22/226006
  3. Abstract:
  4. We study an S = 1/2 Heisenberg model on the honeycomb lattice with first and second neighbor antiferromagnetic exchange (J1-J2 model), employing exact diagonalization in both the Sz = 0 basis and nearest neighbor singlet valence bond (NNVB) basis. We find that for 0.2 < J2/J1 < 0.3, the NNVB basis gives a proper description of the ground state in comparison with the exact results. By analyzing the dimer-dimer as well as the plaquette-plaquette correlations and also defining appropriate structure factors, we investigate possible symmetry breaking states as the candidates for the ground state in the frustrated region. We provide a body of evidence in favor of plaquette valence bond ordering for 0.2 < J 2/J1 < 0.3. By further increasing the ratio J 2/J1, this state undergoes a transition to the staggered dimerized state
  5. Keywords:
  6. Antiferromagnetic exchange ; Dimerized state ; Exact diagonalization ; Exact results ; Heisenberg antiferromagnets ; Heisenberg models ; Honeycomb lattices ; Nearest neighbors ; Structure factors ; Symmetry-breaking ; Valence bonds ; Antiferromagnetic materials ; Antiferromagnetism ; Ground state ; Honeycomb structures
  7. Source: Journal of Physics Condensed Matter ; Volume 23, Issue 22 , 2011 ; 09538984 (ISSN)
  8. URL: http://iopscience.iop.org/article/10.1088/0953-8984/23/22/226006/meta