Magnetic susceptibility measured for CaV4O9 is analyzed by a method with high temperature expansion. The analysis is consistent with the g-value which is close to 2 and is observed by an ESR experiment. Four exchange parameters in a two-dimensional Heisenberg model are determined to represent CaV4O9. All the exchange parameters are about 500 K and strongly frustrated. The observed spin gap orig...

The ground state and the finite temperature phase diagrams with respect to magnetic configurations are studied systematically for thin magnetic films in terms of a classical Heisenberg model including magnetic dipole-dipole interaction and uniaxial anisotropy. Simple relations are derived for the occurrence of the various phase boundaries between the different regions of the magnetic orientatio...

The glN and Uq(glN ) quantum spin chains in the presence of integrable spin impurities are considered. Within the Bethe ansatz formulation, we derive the associated transmission amplitudes, and the corresponding transmission matrices –representations of the underlying quadratic algebra– that physically describe the interaction between the various particle-like excitations displayed by these mod...

We give a review of the elementary properties of spin chains together with some applications to the enumeration of alternating sign matrices. The main references concerning spin chains are [1, 2].

We have studied the S = 1/2 antiferromagnetic Heisenberg model in two dimensions, with an additional Ising next-nearest neighbour interaction. The next-nearest neighbour Ising interaction breaks the isotropy in spin space, for a ferromagnetic next-nearest neighbour interaction the system will order antiferromagnetically along the z axis. Antiferromagnetic next-nearest neighbour interactions wil...

Using an exact mapping transformation method, magnetic properties of a spin-1/2 and spin-1 doubly decorated Ising-Heisenberg model are investigated in detail. By assuming that both interaction parameters are ferromagnetic, we found in addition to an usual ferromagnetic phase another two phases with a nontrivial long-range order.

in this paper, biharmonic slant helices are studied according to bishop frame in the heisenberg group heis3. we give necessary and sufficient conditions for slant helices to be biharmonic. the biharmonic slant helices arecharacterized in terms of bishop frame in the heisenberg group heis3. we give some characterizations for tangent bishop spherical images of b-slant helix. additionally, we illu...

We study the equations for the quasi-momenta which characterize the wave-functions in the Bethe ansatz for the XXX-Heisenberg model. We show in a simple analytical fashion, that the usual " string hypothesis " incorrectly predicts the number of real solutions and the 1