IFLP   13074
INSTITUTO DE FISICA LA PLATA
Unidad Ejecutora - UE
artículos
Título:
Quantum phases in the frustrated Heisenberg model on the bilayer honeycomb lattice
Autor/es:
H. ZHANG; M. ARLEGO; C. A. LAMAS
Revista:
PHYSICAL REVIEW B
Editorial:
AMER PHYSICAL SOC
Referencias:
Lugar: New York; Año: 2014 vol. 89 p. 24403 - 24413
ISSN:
1098-0121
Resumen:
We use a combination of analytical and numerical techniques to study the
phase diagram of the frustrated Heisenberg model on the bilayer
honeycomb lattice. Using the Schwinger-boson description of the spin
operators followed by a mean-field decoupling, the magnetic phase
diagram is studied as a function of the frustration coupling J2 and the interlayer coupling J⊥.
The presence of both magnetically ordered and disordered phases is
investigated by means of the evaluation of ground-state energy, spin
gap, local magnetization, and spin-spin correlations. We observe a phase
with a spin gap and short-range Néel correlations that survives for
nonzero next-nearest-neighbor interaction and interlayer coupling.
Furthermore, we detect signatures of a reentrant behavior in the melting
of the Néel phase and symmetry restoring when the system undergoes a
transition from an on-layer nematic valence-bond crystal phase to an
interlayer valence-bond crystal phase. We complement our work with exact
diagonalization on small clusters and dimer-series expansion
calculations, together with a linear spin-wave approach to study the
phase diagram as a function of the spin S, the frustration, and the interlayer couplings.