Related papers: A Monte Carlo Study of Correlations in Quantum Spi…
We study the spin excitation spectra of the two-dimensional spin-$1/2$ Heisenberg model with a checkerboard structures using stochastic analytic continuation of the imaginary-time correlation function obtained from a quantum Monte Carlo…
Using magnetic neutron scattering we characterize an unusual low temperature phase in orthorhombic SrCuO2. The material contains zigzag spin ladders formed by pairs of S=1/2 chains (J=180 meV) coupled through a weak frustrated interaction…
Using the spherically symmetric self-consistent Green's function method, we consider thermodynamic properties of the $S=1/2$ $J_1$-$J_2$ Heisenberg model on the 2D square lattice. We calculate the temperature dependence of the spin-spin…
The antiferromagnetic Heisenberg chain is expected to have an extended symmetry, [SU(2)xSU(2)]/Z 2 , in the infrared limit, whose physical interpretation is that the spin and dimer order parameters form the components of a common…
The N\'eel temperature, $T_{\rm N}$, of quasi-one- and quasi-two-dimensional antiferromagnetic Heisenberg models on a cubic lattice is calculated by Monte Carlo simulations as a function of inter-chain (inter-layer) to intra-chain…
Dynamical correlations of Jeff = 1/2 isospins in the paramagnetic state of spin-orbital Mott insu- lator Sr2IrO4 was revealed by resonant magnetic x-ray diffuse scattering. We found two-dimensional antiferromagnetic fluctuation with a large…
We present a direct comparison of the recently-proposed valence bond entanglement entropy and the von Neumann entanglement entropy on spin 1/2 Heisenberg systems using quantum Monte Carlo and density-matrix renormalization group…
The nuclear spin-lattice relaxation rate (1/T1) at the V sites in CaV2O5 was measured. The result was compared with the calculation for the two-leg ladder with the strong-coupling expansion. We found a good agreement on the temperature and…
We simulate the dynamical spin structure factor (DSSF) $\mathcal{S}({q},\omega)$ of the spin-1/2 Heisenberg antiferromagnetic chain using classical simulations. By employing Landau-Lifshitz Dynamics, we emulate quantum correlations through…
We investigate the low-temperature properties of the spin-1 antiferromagnetic Heisenberg chain with bond-alternation by the quantum Monte Carlo method (loop algorithm). The strength of bond-alternation at the gapless point is estimated as…
We describe random loop models and their relations to a family of quantum spin systems on finite graphs. The family includes spin 1/2 Heisenberg models with possibly anisotropic spin interactions and certain spin 1 models with…
We investigate the influence of an inter-chain coupling on the spiral ground state correlations of a spin-1/2 Heisenberg model consisting of a two-dimensional array of coupled chains with nearest (J1) and frustrating next-nearest neighbor…
We use the coupled cluster method for infinite chains complemented by exact diagonalization of finite periodic chains to discuss the influence of a third-neighbor exchange J3 on the ground state of the spin-1/2 Heisenberg chain with…
We consider the Ising phase of the antiferromagnetic XXZ Heisenberg chain on a finite-size lattice with N sites.We compute the large $N$ behavior of the spin stiffness, obtaining the correlation length \xi. We use our results to discuss the…
We show how correlation functions of the spin-1/2 Heisenberg chain without magnetic field in the anti-ferromagnetic ground state can be explicitly calculated using information contained in the quantum Knizhnik-Zamolodchikov equation [qKZ].…
Quantum Monte Carlo and density-matrix renormalization group methods are used to study the coupled spin-pseudospin Hamiltonian in one-dimension (1D) that models the charge-ordering instability of the anisotropic Hubbard ladder at quarter…
By using variational wave functions and quantum Monte Carlo techniques, we investigate the complete phase diagram of the Heisenberg model on the anisotropic triangular lattice, where two out of three bonds have super-exchange couplings $J$…
Describing correlated electron systems near phase transitions has been a major challenge in computational condensed-matter physics. In this paper, we apply highly accurate fixed node quantum Monte Carlo techniques, which directly work with…
We study Heisenberg spin-1/2 and spin-1 chains with alternating ferromagnetic ($J_1^F$) and antiferromagnetic ($J_1^A$) nearest-neighbor interactions and a ferromagnetic next-nearest-neighbor interaction ($J_2^F$). In this model frustration…
Using the coupled cluster method (CCM) we study the full (zero-temperature) ground-state (GS) phase diagram of a spin-half ($s=1/2$) $J_{1}$-$J_{2}$ Heisenberg model on a cross-striped square lattice. Each site of the square lattice has 4…