Quantum discord and other measures of quantum correlation
Year: 2011
Type: preprint
Abstract: One of the best signatures of nonclassicality in a quantum system is theexistence of correlations that have no classical counterpart. Different methods
for quantifying the quantum and classical parts of the correlations are amongst
the most actively-studied topics of quantum information theory in the past
decade. Entanglement is the most prominent of these correlations, but in many
cases unentangled states exhibit nonclassical behavior. Thus distinguishing
quantum correlation other than entanglement provides a better division between
the quantum and classical worlds, especially when considering mixed states.
Here we review different notions of classical and quantum correlations
quantified by quantum discord and other related measures. In the first half we
review the mathematical properties of the measures of quantum correlation,
relate them to each other, and discuss the classical-quantum division that is
common among them. In the second half, we show that the measures quantum
correlation identify and quantify the deviation from classicality in various
quantum information-processing tasks, quantum thermodynamics, open-system
dynamics, and many-body physics. We show that in many cases quantum
correlations indicate an advantage of quantum methods over classical ones.
Source: arXiv (Cornell University)
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2912430136