We study the scaling of quantum discord (a measure of quantum correlation beyond entanglement) in spin models analytically and systematically. We find that at finite temperature the block scaling of quantum discord satisfies an area law for any two-local Hamiltonian. We show that generically and heuristically the two-site scaling of quantum discord is similar to that of correlation functions. In particular, at zero temperature it decays exponentially and polynomially in gapped and gapless (critical) systems, respectively; at finite temperature it decays exponentially in both gapped and gapless systems. We compute the two-site scaling of quantum discord in the $XXZ$ chain, the $XY$ chain (in a magnetic field), and the transverse field Ising chain at zero temperature.We study the scaling of quantum discord (a measure of quantum correlation beyond entanglement) in spin models analytically and systematically. We find that at finite temperature the block scaling of quantum discord satisfies an area law for any two-local Hamiltonian. We show that generically and heuristically the two-site scaling of quantum discord is similar to that of correlation functions. In particular, at zero temperature it decays exponentially and polynomially in gapped and gapless (critical) systems, respectively; at finite temperature it decays exponentially in both gapped and gapless systems. We compute the two-site scaling of quantum discord in the $XXZ$ chain, the $XY$ chain (in a magnetic field), and the transverse field Ising chain at zero temperature.

arXiv:1307.6034Physical Review BFeb 11, 201463 citations

Quantum Discord of Certain Two-Qubit States

Jianming Zhou, Xiaoli Hu, Naihuan Jing

arXiv:2004.11668International Journal of Theoretical PhysicsNov 19, 201914 citations

Thermal quantum discord in the Heisenberg chain with impurity

Jia-Min Gong, Zhanqiang Hui

arXiv:1401.3819Physica B Condensed MatterMar 23, 20145 citations

Quantum Entanglement and Quantum Discord in Gaussian Open Systems

Аурелиан Исар, Mădălin O. Bunoiu, Iosif Malaescu

In the framework of the theory of open systems based on completely positive quantum dynamical semigroups, we give a description of the continuous‐variable quantum entanglement and quantum discord for a system consisting of two noninteracting modes embedded in a thermal environment. Entanglement and discord are used to quantify the quantum correlations of the system. For all values of the temperature of the thermal reservoir, an initial separable Gaussian state remains separable for all times. In the case of an entangled initial Gaussian state, entanglement suppression (entanglement sudden death) takes place for non‐zero temperatures of the environment. Only for a zero temperature of the thermal bath the initial entangled state remains entangled for finite times. We analyze the time evolution of the Gaussian quantum discord, which is a measure of all quantum correlations in the bipartite state, including entanglement, and show that quantum discord decays asymptotically in time under the effect of the thermal bath.In the framework of the theory of open systems based on completely positive quantum dynamical semigroups, we give a description of the continuous‐variable quantum entanglement and quantum discord for a system consisting of two noninteracting modes embedded in a thermal environment. Entanglement and discord are used to quantify the quantum correlations of the system. For all values of the temperature of the thermal reservoir, an initial separable Gaussian state remains separable for all times. In the case of an entangled initial Gaussian state, entanglement suppression (entanglement sudden death) takes place for non‐zero temperatures of the environment. Only for a zero temperature of the thermal bath the initial entangled state remains entangled for finite times. We analyze the time evolution of the Gaussian quantum discord, which is a measure of all quantum correlations in the bipartite state, including entanglement, and show that quantum discord decays asymptotically in time under the effect of the thermal bath.

AIP conference proceedingsJan 1, 20110 citations

XXZ

chain, the

XY

chain (in a magnetic field), and the transverse field Ising chain at zero temperature.