Articulo
Quantum disordered phase on the frustrated honeycomb lattice
Registro en:
issn:1098-0121
issn:1550-235X
Autor
Cabra, Daniel Carlos
Lamas, Carlos Alberto
Rosales, Héctor Diego
Institución
Resumen
In the present paper we study the phase diagram of the Heisenberg model on the honeycomb lattice with antiferromagnetic interactions up to third neighbors along the line J₂=J₃ that includes the point J₂=J₃=J₁/2, corresponding to the highly frustrated point where the classical ground state has macroscopic degeneracy. Using the linear spin-wave theory and the Schwinger boson technique followed by a mean field decoupling and exact diagonalization for small systems, we find an intermediate phase with a spin gap and short-range Néel correlations in the strong quantum limit S=½. All techniques provide consistent results which allow us to predict the existence of a quantum disordered phase, which may have been observed in recent high-field ESR measurements in manganites. Instituto de Física La Plata