相关论文: Random Antiferromagnetic SU(N) Spin Chains
Using group theoretical methods we show for both the triangular and square lattices that in the continuum limit the antiferromagnetic order parameter lives on SO3 without respect of the initial lattice. For the antiferromagnetic chain we…
We investigate the magnetic susceptibility $\chi(T)$ of quantum spin chains of $N=1280$ spins with power-law long-range antiferromagnetic coupling as a function of their spatial decay exponent $\alpha$ and cutoff length $\xi$. The…
Entanglement spectra (ES) for the critical SU(N) (2 <= N <= 4) spin chains and other integrable models of finite length are studied with the density matrix renormalization group method. For all models under investigation, the level spacings…
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 report our density matrix renormalization-group and analytical work on S=1 antiferromagnetic Heisenberg spin chains. We study the finite size behavior within the framework of the non-linear sigma model. We study the effect of…
We study states with spontaneous spin current, emerging in frustrated antiferromagnetic spin-$S$ chains subject to a strong external magnetic field. As a numerical tool, we use a non-Abelian symmetry realization of the density matrix…
The effect of quenched disorder on the low-energy and low-temperature properties of various two- and three-dimensional Heisenberg models is studied by a numerical strong disorder renormalization group method. For strong enough disorder we…
Finite-temperature local spin dynamics within the random spin-1/2 antiferromagnetic Heisenberg chain is studied numerically. The aim is to explain measured NMR spin-lattice relaxation times in BaCu_{2}(Si_{0.5}Ge_{0.5})_{2}O_{7}, which is…
We extend the recently introduced strong disorder renormalization group method in real space, well suited to study bond disordered antiferromagnetic power law coupled quantum spin chains, to study excited states, and finite temperature…
We study the R\'enyi entanglement entropy and the Shannon mutual information for a class of spin-1/2 quantum critical XXZ chains with random coupling constants which are partially correlated. In the XX case, distinctly from the usual…
Motivated by recent experiments on chemically synthesized magnetic molecular chains we investigate the lowest lying energy band of short spin-$s$ antiferromagnetic Heisenberg chains focusing on effects of open boundaries. By numerical…
We consider an antiferromagnetic four leg spin-1/2 tube using abelian and non-abelian bosonization. We show that in the limit of weak interchain coupling, the most relevant interaction gives rise to an emergent SU(3)} symmetry, broken only…
A continuum limit treatment of planar spin chains with arbitrary S is presented. The difference between integer and half-integer spins is emphasised. While isotropic half-integer spin chains are gapless,and have power-law decay of…
We demonstrate that the concept of quantum typicality allows for significant progress in the study of real-time spin dynamics and transport in quantum magnets. To this end, we present a numerical analysis of the spin-current autocorrelation…
We report a neutron scattering study of the spin correlations for the spin 5/2, two-dimensional antiferromagnet Rb_2MnF_4 in an external magnetic field. Choosing fields near the system's bicritical point, we tune the effective anisotropy in…
The $S=1/2$ Heisenberg chains with bond alternation and randomness on the strong bonds are studied by the density matrix renormalization group method. It is assumed that the odd-th bond is antiferromagnetic with strength $J$ and even-th…
Linear Heisenberg antiferromagnets (HAFs) are chains of spin-$S$ sites with isotropic exchange $J$ between neighbors. Open and periodic boundary conditions return the same ground state energy in the thermodynamic limit, but not the same…
We address the issue of universality in two-dimensional disordered Ising systems, by considering long, finite-width strips of ferromagnetic Ising spins with randomly distributed couplings. We calculate the free energy and spin-spin…
We present results on the low-frequency dynamical and transport properties of random quantum systems whose low temperature ($T$), low-energy behavior is controlled by strong disorder fixed points. We obtain the momentum and frequency…
We present exact analytic results for the energy of a SU(N) repulsive Fermi gas as a function of the spin-channel occupation at second order in the gas parameter. This is an extension of an old result that now incorporates the degree of…