A study of Quantum Correlations in Open Quantum Systems

Chakrabarty, Indranil; Banerjee, Subhashish; Siddharth, Nana

doi:10.48550/arxiv.1006.1856

Cited by 3 publications

(3 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Meanwhile, the non-classical correlation is measured by the so-called quantum discord [3], which is the difference of the total amount of correlations and the classical correlation. Over the past decade, quantum discord has received a lot of attention, including analytic calculations for some special two-qubit sates [4,5], detecting of quantum discord [6][7][8][9][10][11][12][13], quantum discord in the concrete physical models [14][15][16][17][18][19][20][21][22][23], the dynamics of quantum discord [24][25][26][27][28][29][30][31][32][33][34][35], quantum discord in continuous variable system [36,37], quantum discord of multipartite states [38], and exploration in the laboratory [39][40][41], etc. Most recently, operational interpretations of quantum discord are proposed in Ref.…”

Section: Introductionmentioning

confidence: 99%

Optimal measurements to access classical correlations of two-qubit states

et al. 2011

Phys. Rev. A

153

138

View full text Add to dashboard Cite

We analyze the optimal measurements to access classical correlations in arbitrary two-qubit states. Two-qubit states can be transformed into the canonical forms via local unitary operations. For the canonical forms, we investigate the probability distribution of the optimal measurements. The probability distribution of the optimal measurements is found to be centralized in the vicinity of a specific von Neumann measurement, which we call the maximal-correlation-direction measurement (MCDM). We prove that, for the states with zero discord and maximally mixed marginals, the MCDM is the optimal measurement. Furthermore, we give an upper bound of quantum discord based on the MCDM, and investigate its performance for approximating the quantum discord.

show abstract

Section: Introductionmentioning

confidence: 99%

Optimal measurements to access classical correlations of two-qubit states

et al. 2011

Phys. Rev. A

153

138

View full text Add to dashboard Cite

show abstract

“…The quantum entanglement dynamics in open quantum systems was broadly investigated in the literature. However, few works dealt with the effect of the environment on quantum discord [33][34][35][36][37].…”

Section: Introductionmentioning

confidence: 99%

Asymptotic dynamics of quantum discord in open quantum systems

Berrada

Eleuch

Hassouni

2011

J. Phys. B: At. Mol. Opt. Phys.

View full text Add to dashboard Cite

To cite this version: It is well known that quantum entanglement makes possible certain tasks in quantum information theory. However, there are also quantum tasks that display the quantum advantage without entanglement. Distinguishing classical and quantum correlations in quantum systems is therefore of both practical and fundamental importance. Realistic quantum systems are not closed and therefore it is important to study the various correlations when the system loses its coherence due to interactions with the environment. In this paper, we study in detail the dynamics of different kinds of correlations, classical correlation, quantum discord, and entanglement in open quantum systems, in particular a two-qubit system evolving under quantum dynamical semigroups of Kossakowski-type of completely positive maps. In such an environment classical and quantum correlations can even persist asymptotically. By analytic and numerical analysis, we find that the quantum discord is larger than the classical correlation for asymptotic states. Furthermore, we show that the quantum discord is more resistant to the action of the environment than the quantum entanglement and it can persist even in the asymptotic long-time regime.

show abstract

“…However, it is expected that as time evolves the quantum correlations [35] generated due to the non-negligible interaction between the two atomic subsystem and the thermal bath degree of freedom i.e.…”

Section: Non Unitary Time Evolution Of the Reduced Subsystemmentioning

confidence: 99%

Open Quantum Entanglement: A study of two atomic system in static patch of de Sitter space

Akhtar,

Choudhury,

Chowdhury

et al. 2019

Preprint

View full text Add to dashboard Cite

In this work, our prime objective is to study non-locality and long-range effect of two-body correlation using quantum entanglement from the various information-theoretic measure in the static patch of De Sitter space using a two-body Open Quantum System (OQS). The OQS is described by two entangled atoms which are surrounded by a thermal bath, which is modelled by a massless probe scalar field. Firstly, we partially trace over the bath field and construct the Gorini Kossakowski Sudarshan Lindblad (GSKL) master equation, which describes the time evolution of the reduced subsystem density matrix. This GSKL master equation is characterized by two components, these are-Spin chain interaction Hamiltonian and the Lindbladian. To fix the form of both of them, using Schwinger-Keldysh formalism we compute the Wightman functions for probe massless scalar field. Using this result along with the large time equilibrium behaviour we obtain the analytical solution for reduced density matrix. Further using this solution we compute Von-Neumann entropy, Re nyi entropy, logarithmic negativity, entanglement of formation, concurrence and quantum discord in a static patch of De Sitter space. Finally, we have studied the violation of Bell-CHSH inequality, which is the key ingredient to study non-locality in primordial cosmology.

show abstract

A study of Quantum Correlations in Open Quantum Systems

Cited by 3 publications

References 48 publications

Optimal measurements to access classical correlations of two-qubit states

Optimal measurements to access classical correlations of two-qubit states

Asymptotic dynamics of quantum discord in open quantum systems

Open Quantum Entanglement: A study of two atomic system in static patch of de Sitter space

Contact Info

Product

Resources

About