Related papers: Structure of end states for a Haldane Spin Chain

Linear-chain nickelates with the composition (Nd_x Y_{1-x})_2 Ba Ni O_5 (x=1, x=0.75, x=0.5, and x=0.25) are studied in a series of neutron scattering experiments. Powder diffraction is used to determine the temperature dependence of the…

This paper overviews the behavior of the end-chain spins of linear chain systems possessing a Haldane gap. The physical properties of the end-chain spins are described by reviewing the results obtained primarily with materials known as…

Inelastic neutron scattering experiments on the S=1 quasi-one-dimensional bond-alternating antiferromagnet Ni(C9D24N4)(NO2)ClO4 have been performed under magnetic fields below and above a critical field Hc at which the energy gap closes.…

Polarized and unpolarized inelastic neutron scattering is used to study Haldane-gap excitations in the mixed-spin linear-chain antiferromagnet Nd2BaNiO5. The longitudinal mode, polarized along the direction of ordered moments, is observed…

We report the results of elastic and inelastic neutron scattering experiments on the Haldane gap quantum antiferromagnet Ni(C5D14N2)2N3(PF6) performed at mK temperatures in a wide range of magnetic field applied parallel to the S = 1 spin…

The antiferromagnetic spin-one chain is considerably one of the most fundamental quantum many-body systems, with symmetry protected topological order in the ground state. Here, we present results for its dynamical spin structure factor at…

Two quasi-1-dimensional S=1 quantum antiferromagnetic materials, PbNi2V2O8 and SrNi2V2O8, are studied by inelastic neutron scattering on powder samples. While magnetic interactions in the two systems are found to be very similar, subtle…

Inelastic neutron scattering experiments on the Haldane-gap quantum antiferromagnet \nd are performed at mK temperatures in magnetic fields of almost twice the critical field $H_c$ applied perpendicular to the spin cahins. Above $H_c$ a…

Electron spin resonance (ESR), at 9, 94, and 190 GHz, and magnetization studies on polycrystalline, powder, and ultrafine powder samples of Ni(C3H10N2)2N3(ClO4) (NINAZ) have revealed several effects arising from the Haldane phase. Using the…

Investigating quantum fluctuations in the ground states of S=1 quantum antiferromagnetic spin chains described by the bilinear-biquadratic Hamiltonian, we study a mechanism of the breakdown of the Haldane phase. Based on the…

We have investigated Haldane's conjecture for the S=2 isotropic antiferromagnetic quantum spin chain with nearest-neighbor exchange J. Using a density matrix renormalization group algorithm for chains up to L=350 spins, we find in the…

We have performed electron spin resonance measurements over a wide frequency and magnetic field range on a single crystal of the S=1 quasi-one-dimensional Heisenberg antiferromagnet $\rm Ni(C_5H_{14}N_2)_2N_3(PF_6)$. We observed gapped…

We consider quasi one dimensional spin-1 Heisenberg chains with crystal field anisotropy in a uniform magnetic field. We determine the dynamical structure factor in various limits and obtain a fairly complete qualitative picture of how it…

The antiferromagnetic Heisenberg spin chain with integer spin has short-range magnetic order and an excitation energy gap above the ground state. This so-called Haldane gap is proportional to the exchange coupling $J$ of the Heisenberg…

We study the behavior of Heisenberg, antiferromagnetic, integer-spin chains in the presence of a magnetic field exceeding the attendant spin gap. For temperatures much smaller than the gap, the spin chains exhibit Luttinger liquid behavior.…

The spin excitation continuum, expected to dominate the low-energy fluctuation spectrum in the Haldane spin chain around the Brillouin zone center, q=0, is directly observed by inelastic magnetic neutron scattering in the S=1 quasi-1D…

Quite a few low-dimensional magnets are quantum-disordered ``spin liquids'' with a characteristic gap in the magnetic excitation spectrum. Among these are antiferromagnetic chains of integer quantum spins. Their generic feature are…

We present a static, model-independent, experimental determination of the spin-spin correlation length \xi in a quantum spin system. This is achieved in doped Haldane (i.e., S=1 Heisenberg antiferromagnetic) chain Y(2)BaNi(1-x)Mg(x)O(5) by…

We present detailed measurement of the non-hydrodynamic part of the spin excitation spectrum in the model quasi-1D S=1 antiferromagnet CsNiCl3 by inelastic magnetic neutron scattering. In the better part of the Brillouin zone the effect of…

Spin chains are among the simplest physical systems in which electron-electron interactions induce novel states of matter. Here we show that the combination of atomic scale engineering and spectroscopic capabilities of state of the art…