An asymptotical separability criterion for bipartite density operators

Abstract

For a given density matrix $\rho$ of a bipartite quantum system an asymptotical separability criterion is suggested. Using the continuous ensemble method, a sequence of separable density matrices is built which converges to $\rho$ if and only if $\rho$ is separable. The convergence speed is evaluated and for any given tolerance parameter $\kappa$ an iterative procedure is suggested which decides in finite number of steps if there exists a separable density matrix $\rho_\kappa$ which differs from the matrix $\rho$ by at most $\kappa$.