Quantum discord and local demons

Abstract

Quantum discord was proposed as a measure of the "quantumness" of correlations. There are at least three different discord-like quantities, two of which determine the difference between the efficiencies of a Szilard's engine under different sets of restrictions. The three discord measures vanish simulataneosly. We introduce an easy way to test for zero discord, relate it to the Cerf-Adami conditional entropy and show that there is no relation between the discord and the local disitnguishability.

7 pages, RevTeX. Some minor changes after comments from colleagues, some references added. Similar to published version

References in corpus (3)

• On the quantum, classical and total amount of correlations in a quantum state
• Vanishing quantum discord is necessary and sufficient for completely positive maps
• How state preparation can affect a quantum experiment: Quantum process tomography for open systems

Cited by in corpus (6)

• Necessary and sufficient condition for non-zero quantum discord
• Interpreting quantum discord through quantum state merging
• Operational interpretations of quantum discord
• Quantum discord for general two--qubit states: Analytical progress
• Entanglement, discord and the power of quantum computation
• Detecting Multipartite Classical States and their Resemblances