Fine structure of the Bethe ansatz for the spin-1/2 Heisenberg XXX model

UvA - DARE ( Digital Academic Repository ) Fine structure of the Bethe Ansatz for the spin - 1 / 2 Heisenberg XXX model

We analyse the Bethe ansalz equations for the two-particle sector of the spin-; Heisenberg X X X model on a one-dimensional lattice of length N . We show that. beginning at a critical lattice length of N = 21.86. new pairs of real solutions develop, whereas complex solutions star1 to disappear. 'Ibe integers (that appear in the logarithmic form of the Bethe equations) of the o w solutions do no...

Ansatz Equations in the XXX - Heisenberg Model

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

Heisenberg Model, Bethe Ansatz, and Random Walks

Heisenberg XXX Model with General Boundaries: Eigenvectors from Algebraic Bethe Ansatz

We propose a generalization of the algebraic Bethe ansatz to obtain the eigenvectors of the Heisenberg spin chain with general boundaries associated to the eigenvalues and the Bethe equations found recently by Cao et al. The ansatz takes the usual form of a product of operators acting on a particular vector except that the number of operators is equal to the length of the chain. We prove this r...

the use of appropriate madm model for ranking the vendors of mci equipments using fuzzy approach

abstract nowadays, the science of decision making has been paid to more attention due to the complexity of the problems of suppliers selection. as known, one of the efficient tools in economic and human resources development is the extension of communication networks in developing countries. so, the proper selection of suppliers of tc equipments is of concern very much. in this study, a ...