Developing Entanglement Verification for Large Bipartite Systems

Abstract

It is a major problem within the field of Quantum Information whether the state of a system is entangled or separable. Exact methods have been developed for two qubit systems, but for larger systems determining the boundary between separable and entangled states has been shown to be NP-hard. An iterative method has been proposed that creates progressively tighter bounds from each direction, but this method is resource limited, and determining the boundary precisely requires an infinite number of iterations. Further, it is also believed that successive iterations scale badly. Instead, a weighted measure is developed over the delineated subspaces, producing a likelihood function by convex optimization. This presentation describes progress towards understanding and deploying this method in support of experimental work involving entangled states.