Superstring sigma models from spin chains:: the SU(1, 1|1) case

We derive the coherent state representation of the integrable spin chain Hamiltonian with non-compact supersymmetry group G = SU(1, 1 vertical bar 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 in the supercoset. The spin chain sigma model is shown to agree with that following from the Green-Schwarz action describing two-charged string spinning on AdS(5) x S-5. (c) 2005 Elsevier B.V. All rights reserved.