Joseph Emerson

Institute for Quantum Computing (IQI)
University of Waterloo

Negativity and non-classicality in discrete phase-space and other quasi-probability representations of quantum theory.

In recent years several quasi-probability representations of finite dimensional quantum mechanics have been proposed as discrete analogs of the Wigner phase space representation of continuous quantum mechanics. I will describe a formalism based on the theory of frames which allows us to characterize the complete set of quasi-probability representations that can be defined for finite dimensional quantum systems. This formalism leads to a direct proof that any quasi-probability representation that faithfully reproduces the quantum statistics can not be fit into a classical stochastic framework. This condition turns out to be equivalent to a proof of contextuality. This formalism should provide definitive criteria for determining whether non-classical resources are required of a given quantum information task.

Seminar schedule: http://www.physics.rutgers.edu/qcg/Seminars.html