A note on spin chain/string duality

Recently a significant progress in matching the anomalous dimensions of certain class of operators in N=4 SYM and rotating strings was made. The correspondence was established mainly by using of Bethe ansatz technique applied to the spin s Heisenberg chain model. In a recent paper Kruczenski (hep-th/0311203) suggested to solve the Heisenberg model by using of sigma model approach. In this paper we generalize the solutions obtained by Kruczenski and comment on the dual string theory. It turns out that our solution is related to a generalized ansatz for rotating strings which can be reduced to the so called Neumann-Rosochatius integrable system. We comment on the spin chain sigma model and string solutions and the possibilities for a more precise formulation of on string/gauge theory correspondence.