We study the ground-state (gs) phase diagram of the frustrated spin-12 J1-J2-J3 antiferromagnet with J 2=J3=κJ1 on the honeycomb lattice using coupled-cluster theory and exact diagonalization methods. We present results for the gs energy, magnetic order parameter, spin-spin correlation function, and plaquette valence-bond crystal (PVBC) susceptibility. We find a Néel antiferromagnetic (AFM) phase for κ<κc1≈0.47, a collinear striped AFM phase for κ>κc2≈0.60, and a paramagnetic PVBC phase for κc1κκc2. The transition at κc2 appears to be of first-order type, while that at κc1 is continuous. Since the Néel and PVBC phases break different symmetries our results favor the deconfinement scenario for the transition at κc1.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Jul 11 2011|