| |
 |
UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 2:24 |
 |
|
|
|
Conference: Bucharest University Faculty of Physics 2021 Meeting
Section: Theoretical Physics and Applied Mathematics
Title:
Dynamics of quantum correlations in Gaussian bosonic channels
Authors:
Aurelian ISAR (1)
Affiliation:
1) Department of Theoretical Physics, National Institute of Physics and Nuclear Engineering, Bucharest-Magurele, Romania
E-mail
isar@theory.nipne.ro
Keywords:
Quantum correlations; quantum coherence; open quantum systems.
Abstract:
An impressive progress in the development of quantum information theory is reached presently from the quantum resource theory approach to quantum correlations, like entanglement, discord and steering, and to quantum coherence. Recently, a framework for the quantification of coherence has been established [1], in which quantum coherence is treated as a resource in a manner similar to quantum entanglement.
In the framework of the theory of open systems based on completely positive quantum dynamical semigroups, we describe the behaviour of continuous variable quantum correlations (entanglement, Gaussian quantum discord, Gaussian quantum steering) and quantum coherence in a system of two (coupled or uncoupled) bosonic modes evolving in a Gaussian noisy channel, in the case of a common environment of the form of a thermal bath or a squeezed thermal bath.
We solve the Markovian master equation for the density operator that describes the time evolution of the considered system and, using the symplectic formalism, we study the quantum correlations and quantum coherence in terms of covariance matrices for Gaussian input states (squeezed vacuum state and squeezed thermal state).
Depending on the initial state of the system, the coefficients describing the interaction of the system with the reservoir and the intensity of the coupling between the two modes, we observe phenomena like generation, suppression, periodic revivals and suppressions, or an asymptotic decay in time of quantum correlations [2-4] and relative entropy of coherence [5, 6].
References:
[1] T. Baumgratz, M. Cramer and M. B. Plenio, Quantifying coherence, Phys. Rev. Lett. 113, 140401 (2014).
[2] A. Isar, Entanglement generation in two-mode Gaussian systems in a thermal environment, Open Sys. Inf. Dynamics 23, 1650007 (2016).
[3] A. Isar and T. Mihaescu, Generation of quantum discord in two-mode Gaussian systems in a thermal reservoir, Eur. Phys. J. D 71, 144 (2017).
[4] T. Mihaescu and A. Isar, Evolution of quantum steering in a Gaussian noisy channel, Eur. Phys. J. D 72, 104 (2018).
[5] J. Xu, Quantifying coherence of Gaussian states, Phys. Rev. A 93, 032111 (2016).
[6] A. Isar, Coherence dynamics of two interacting bosonic modes in a thermal environment, Eur. Phys. J. Web Conf. 226, 01006 (2020).
|
|
|
|