Anisotropic frustrated Heisenberg model on the honeycomb lattice

ANSGAR KALZ; MARCELO ARLEGO; DANIEL CABRA; ANDREAS HONECKER; GERARDO ROSSINI

PHYSICAL REVIEW B

AMER PHYSICAL SOC

Lugar: New York; Año: 2012 vol. 85 p. 104505 - 10450510

1098-0121

We investigate the ground-state phase diagram of an anisotropic Heisenberg model on the honeycomb lattice with competing interactions. We use quantum Monte Carlo simulations, as well as linear spin-wave and Ising series expansions, to determine the phase boundaries of the ordered magnetic phases. We find a region without any classical order in the vicinity of a highly frustrated point. Higher-order correlation functions in this region give no signal for long-range valence-bond order. The low-energy spectrum is derived via exact diagonalization to check for topological order on small-size periodic lattices.