Eur. Phys. J. Plus (2022) 137: 625
https://doi.org/10.1140/epjp/s13360-022-02838-w

Regular Article

Relations between the quantum correlation entropy and quantum discord for X-states in multipartite systems

¹ Department of Mathematics, South China University of Technology, 510640, Guangzhou, People’s Republic of China
² Laboratory of Quantum Science and Engineering, South China University of Technology, 510641, Guangzhou, People’s Republic of China

^b zhengzj@scut.edu.cn

Received: 5 April 2022
Accepted: 16 May 2022
Published online: 25 May 2022

Abstract

Observational entropy is a generalization of Boltzmann entropy to quantum mechanics. Observational entropy based on coarse-grained measurements has a certain relations with other quantum information measures. Quantum correlation entropy and quantum discord are both physical quantities used to measure quantum correlation. The former is based on local observational entropy. The latter is based on von Neumann projection measurements acting on some subsystems. We study the relations between quantum correlation entropy and quantum discord for N-partite X-states with 4-dimensional subsystems.