A system theory proof of the infeasibility of entanglement generation in Gaussian quantum systems via classical control

This paper uses a system theoretic approach to show that classical linear time invariant controllers cannot generate steady state entanglement in a bipartite Gaussian quantum system which is initialized in a Gaussian state. The paper also shows that the use of such controllers cannot generate entanglement in a finite time from a bipartite system initialized in a separable Gaussian state. The approach reveals connections between systems theoretic concepts and the well known physical principle that local operations and classical communications cannot generate entangled states starting from separable states.