An interest in the theoretical study of quantum spin chains exhibiting spin–Peierls phases has incredibly grown since the discovery of the first inorganic spin–Peierls compound CuGeO3 (for a review see). Although the quantum Heisenberg model is usually used as an appropriate model to describe the spin–Peierls phase transition in the available materials some generic features can be clarified wit...

The paper presents a numerical approach for the calculation of thermodynamics and spin correlations for spin-2 XY chains. To illustrate the approach we performed exact finite-chain calculations of all time-dependent two-spin correlation functions for the spin-2 Ising chain in the transverse field. The computed correlation functions permit to evaluate the frequency-dependent susceptibilities and...

We consider the Super Yang–Mills/spin system map to construct the SU(2) spin bit model at the level of two loops in Yang–Mills perturbation theory. The model describes a spin system with chaining interaction. In the large N limit the model is shown to be reduced to the two loop planar integrable spin chain.

The theory of magnetic symmetry in quasicrystals, described in a companion paper [Acta Crystallographica AXX (2003) xxx-xxx], is used to enumerate all 3-dimensional octagonal spin point groups and spin space-group types, and calculate the resulting selection rules for neutron diffraction experiments. 1. Introduction We enumerate here all three-dimensional octagonal spin groups and calculate the...

In this article we apply a recently invented analytical real-space renormalization group formulation which is based on numerical concepts of the density matrix renormalization group. Within a rigorous mathematical framework we construct non-perturbative renormalization group transformations for the spin1 2 XXX Heisenberg model in the finite temperature regime. The developed renormalization grou...

We consider the Super Yang–Mills/spin system map to construct the SU(2) spin bit model at the level of two loops in Yang–Mills perturbation theory. The model describes a spin system with chaining interaction. In the large N limit the model is shown to be reduced to the two loop planar integrable spin chain.

Through an h̄-expansion of the confined Calogero model with spin exchange interactions, we extract a generating function for the involutive conserved charges of the FrahmPolychronakos spin chain. The resulting conservation laws possess the spin chain yangian symmetry, although they are not expressible in terms of these yangians. 08/00 (revised: 02/01) 1 Work supported by NSERC (Canada) and FCAR ...

Missing.... xxxx xxxx xxxxxx xxxx xxx xx xxxxxx xxxxxxx xxxxxx xxxx xxxxxx. Xxxxx xxxx xx xxxxxx xxxxx xxxx xxxxxxxxxx xxxxxx xxxxx xxxx xxxxxx xxxxx xxxxxx xxxxxx xxxxx. Xxxxxxxx xxxxxxx xxxxxx xxx xxxxxx, xxxxxx xxxxxxx xxxxx xxxx xxx xxxxx xxxxx xxxxxxxxxxx. Xxxxxx xxxxx xxxxxx xxxxxxxxx xxxxxxxx xxxxxx xxx xxxxx xxx xxxxxxx xxxxx xxxxx xxxxx xxxxx. Xxxxxx xxxx xxxxxxx, xxxxxxx xxxxxx xxx xx...

We study the continuum limit of the spin-1 chain in the non-Abelian bosonization approach of Affleck and show that the Hamiltonian of integrable spin-1 chain yields the Lagrangian of supersymmetric sine-Gordon model in the zero lattice spacing limit. We also show that the quantum group generators of the spin-1 chain give non-local charges of the supersymmetric sine-Gordon theory. PACS numbers: ...

We derive the coherent state representation of the integrable spin chain Hamil-tonian with non-compact supersymmetry group G =SU(1, 1|1). By passing to the continuous limit, we find a spin chain sigma model describing a string moving on the supercoset G/H, H being the stabilizer group. The action is written in a manifestly G-invariant form in terms of the Cartan forms and the string coordinates...