Reflected entropy: Not a correlation measure
Patrick Hayden, Marius Lemm, and Jonathan Sorce
Phys. Rev. A 107, L050401 (2023) - Published 30 May, 2023
For a quantum state of two coupled physical systems, a correlation measure is a quantity that measures how much each system knows about the other. Here, the authors show that the quantity known as “reflected entropy” is not a correlation measure, by constructing quantum states on three coupled systems for which the reflected entropy increases when one of the systems is discarded.
Distribution of genuine high-dimensional entanglement over 10.2 km of noisy metropolitan atmosphere
Lukas Bulla, Kristian Hjorth, Oskar Kohout, Jan Lang, Sebastian Ecker, Sebastian P. Neumann, Julius Bittermann, Robert Kindler, Marcus Huber, Martin Bohmann, Rupert Ursin, and Matej Pivoluska
Phys. Rev. A 107, L050402 (2023) - Published 30 May, 2023
The authors investigate the dimensionality of photonic quantum entanglement distributed through a 10.2-km atmospheric link connecting a building in the center of Vienna to a distant laboratory in Bisamberg. An atypical approach to time-bin encoding was employed to analyze the data. The results show that the distributed data cannot be explained by qubits alone, indicating the presence of high-dimensional entanglement in the system.














