Date:
Tue, 21/08/201812:00-14:00
Location:
Danciger B building, Seminar room
Lecturer: Dr. Dlie Wolf, Perimeter Institute for Theoretical Physics, Waterloo, Ontario, Canada
Abstract:
It is well known that correlations predicted by quantum mechanics cannot be explained by any classical (local-realistic) theory. The relative strength of quantum and classical correlations is usually studied in the context of Bell inequalities, but this tells us little about the geometry of the quantum set of correlations. In other words, we do not have good intuition about what the quantum set actually looks like. By studying the geometry of the quantum set using standard tools from convex geometry we find counter-intuitive features in the simplest non-trivial Bell scenario (two parties, two inputs and two outputs). Surprising examples include the prevalence of flat regions in portions of the quantum boundary, as well as finding that not all extremal points of the quantum boundary are "exposed" in the sense of being uniquely identifiable by some hyperplane tangent to the boundary.
Abstract:
It is well known that correlations predicted by quantum mechanics cannot be explained by any classical (local-realistic) theory. The relative strength of quantum and classical correlations is usually studied in the context of Bell inequalities, but this tells us little about the geometry of the quantum set of correlations. In other words, we do not have good intuition about what the quantum set actually looks like. By studying the geometry of the quantum set using standard tools from convex geometry we find counter-intuitive features in the simplest non-trivial Bell scenario (two parties, two inputs and two outputs). Surprising examples include the prevalence of flat regions in portions of the quantum boundary, as well as finding that not all extremal points of the quantum boundary are "exposed" in the sense of being uniquely identifiable by some hyperplane tangent to the boundary.