Local Models of Entanglement

Ryan Lanzetta

Mentor: Professor Alexios Polychronakos

Entanglement and non-locality are often thought to coincide. While this is true for pure states, the situation is more complicated for mixed states, as some mixed, entangled states can be simulated with local hidden variable models. Werner constructed a family of mixed states with the property that some entangled states in the family have descriptions in terms of local hidden variables. We explicitly construct a local hidden variable model for a state in the family having this property. Additionally, we discuss the amount of mixed-ness that is tolerated before an entangled state in the family ceases to be non-local—a question that remains open.

The Bloch ball representation of a single-qubit density matrix.