Magnetic properties of a spin-1/2 quadrumer chain

Abstract

We study a novel S=1/2 cluster chain Hamiltonian which has recently been proposed in the context of the charge ordered low-temperature phase of alpha'-NaV2O5. We perform a detailed investigation of this model within a large range of parameters using perturbation theory and Lanczos diagonalization. Using model-specific local conservation laws and parameter-dependent mappings to various effective low-energy Hamiltonians we uncover a rich phase diagram and several regimes of gapful spin-excitations. We find that the overall features of recent neutron scattering data on alpha'-NaV2O5 can be fitted within this model, however using a set of parameters which seems unlikely.

9 pages REVTeX, 11 PostScript figures included using psfig.sty; final version to appear in Phys. Rev. B: New appendix, modified Figs. 1 & 10 and other small changes

References in corpus (5)

• First-order quantum phase transition in the orthogonal-dimer spin chain
• Response: Spin-Singlet clusters in the ladder compound NaV2O5
• Can a frustrated spin-cluster model describe the low-temperature physics of NaV_2O_5 ?
• Magnetic excitations in charge- ordered NaV2O5
• Discussion of a spin-cluster model for the low temperature phase of NaV_2O_5

Cited by in corpus (5)

• Dynamic and thermodynamic properties of the generalised diamond chain model for azurite
• Sign-problem-free Monte Carlo simulation of certain frustrated quantum magnets
• Magneto-thermal properties of the Heisenberg-Ising orthogonal-dimer chain with triangular XXZ-clusters
• A microscopic model for the structural transition and spin gap formation in alpha'-NaV2O5
• Disordered ground states in a quantum frustrated spin chain with side chains