Quantum Science Seminar

Communicating Entanglement

Ryan ReichMathematics Department, University of Michigan, Ann Arbor

An interdisciplinary group of faculty & students studies problems in the theory of quantum information processing. A brief review of the most recent publications will be followed by a presentation on a specific paper or set of papers. All faculty and students are welcome.
Quantum entanglement is a negative quantity: a pure state is entangled if it is not a product state. Almost every state is therefore entangled, and so not classical, and in order to express different "degrees" of entanglement, one can try to understand which transformations of states can be achieved in a bipartite system in which the parts transform separately and communicate only by classical means. These transformations are characterized by the end state "majorizing" the start state, meaning intuitively that the transformation must skew the start state's amplitudes towards those that are more likely, preventing it from increasing entanglement.

Sponsored by