“School of Physics”

Back to Papers Home
Back to Papers of School of Physics

Paper   IPM / P / 12120
School of Physics
  Title:   Plaquette Valence Bond Ordering in a J1-J2 Heisenberg Antiferromagnet on a Honeycomb Lattice
1.  H. Mosadeq
2.  F. Shahbazi
3.  S.A. Jafari
  Status:   Published
  Journal: J. Physics: Condens. Matter
  Vol.:  23
  Year:  2011
  Pages:   226006 (10pp)
  Supported by:  IPM
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 < J2/J1 < 0.3. By further increasing the ratio J2/J1, this state undergoes a transition to the staggered dimerized state.

Download TeX format
back to top
scroll left or right