Matrix product representations for spin-(1/2) and spin-(3/2) spontaneous quantum ferrimagnets

¹  Department of Physics, Sharif University of Technology - P.O. Box 11155-9161, Tehran, Iran
²  Department of Physics, Iran University of Science and Technology - P.O. Box 16765-163, Tehran, Iran

Corresponding authors: salipour@physics.sharif.edu sbaghbanzadeh@physics.iust.ac.ir vahid@sharif.edu

Received: 16 June 2008
Accepted: 5 November 2008

Abstract

Using the matrix product formalism, we find exact ground states for two new spin-() and spin-() quantum chains. On a lattice of sites, these ground states have a total spin of , and hence have ferrimagnetic character. The novel point of this construction is that we construct a matrix product representation, not for a state which is invariant under rotation as has been hitherto considered, but for a state which transforms to other states under this symmetry operation. The method can be directly generalized to other symmetry groups.