Southwest Quantum Information and Technology

Nonzero classical discord

Presenting Author: Vlad Gheorghiu, Institute for Quantum Science and Technology and Institute for Quantum Computing
Contributing Author(s): Marcos C. de Oliveira, Barry Sanders

Quantum discord is the quantitative difference between two alternative expressions for bipartite mutual information, given respectively in terms of two distinct definitions for the conditional entropy. By constructing a stochastic model of shared states, classical discord can be similarly defined, quantifying the presence of some stochasticity in the measurement process. Therefore, discord can generally be understood as a quantification of the system's state disturbance due to local measurements, be it quantum or classical. We establish an operational meaning of classical discord in the context of state merging with noisy measurement and thereby show the quantum-classical separation in terms of a negative conditional entropy.

Read this article online: http://dx.doi.org/10.1103/PhysRevLett.115.030403

(Session 5 : Thursday from 5:00 - 7:00 pm)