The su q(1,1) q-coherent states and their nonclassical properties

The su _q(1,1) q-coherent states ( q-CSs) are composed of two subspaces and they are shown to satisfy a unity resolution relation. A matrix realization of su _q(1,1) is obtained in terms of a q-derivative operator. Nonclassical properties of the su _q(1,1) q-CSs are also studied. It is found that the su _q(1,1) q-CSs are the minimum uncertainty states of the su _q(1,1) algebra, and the two subspaces of them exhibit very different nonclassical properties.