Entanglement detection criterion for continuous variable Gaussian states from the moments of partially transposed density matrices

Entanglement criteria and measures that are based on moments of the partially transposed density matrix are attractive because they are experimentally accessible, even for mixed states. In this paper, we formulate one such criterion for bipartite continuous variable Gaussian states. We demonstrate that the criterion is equally effective in measuring entanglement as the von Neumann entropy in a representative semiclassical ground state of a generalized Dicke model.