Quenching the Haldane Gap in Spin-1 Heisenberg Antiferromagnets (original) (raw)

We consider a quasi-one-dimensional system of spin-1 Heisenberg antiferromagnetic chains arranged in 2D and 3D hypercubic lattices with interchain coupling J and uniaxial single-ion anisotropy D. Using large scale numerical simulations, we map out the J − D phase diagram and investigate the low lying excitations of the Haldane phase in the quasi-one-dimensional limit. We also probe directly the non-local string order parameter in the Haldane phase in order to demonstrate the topological nature of this phase.