Ground state properties of antiferromagnetic anisotropic S=1 Heisenberg spin chains

Peters, D., McCulloch, I.P.(2), Selke, W.
Institut für Theoretische Physik, Technische Hochschule Aachen,
D-52056 Aachen, Germany and (2) Department of Physics, University of Queensland, Brisbane, QLD 4072, Australia


Using (infinite) density matrix renormalization group techniques, ground state properties of antiferromagnetic S=1 Heisenberg spin chains with exchange and single--site anisotropies in an external field are studied. The phase diagram is known to display a plenitude of interesting phases. We elucidate quantum phase transitions between the supersolid and spin--liquid as well as the spin--liquid and the ferromagnetic phases. Analyzing spin correlation functions in the spin--liquid phase, commensurate and (two distinct) incommensurate regions are identified.