English
Related papers

Related papers: Frozen discord in stochastic dephasing environment

200 papers

We address the dynamics of entanglement and quantum discord for two non interacting qubits initially prepared in a maximally entangled state and then subjected to a classical colored noise, i.e. coupled with an external environment…

Quantum Physics · Physics 2013-06-06 C. Benedetti , F. Buscemi , P. Bordone , M. G. A. Paris

As a universal quantum character of quantum correlation, the freezing phenomenon is researched by geometry and quantum discord methods, respectively. In this paper, the properties of R`enyi discord is studied for two independent Dimer…

Quantum Physics · Physics 2018-04-10 Xiao-Yu Li , Qin-Sheng Zhu , Ming-Zheng Zhu , Hao Wu , Shao-Yi Wu , Ming-Chuan Zhu

We evaluate the quantum discord dynamics of two qubits in independent and common non-Markovian environments. We compare the dynamics of entanglement with that of quantum discord. For independent reservoirs the quantum discord vanishes only…

Quantum Physics · Physics 2015-03-13 F. F. Fanchini , T. Werlang , C. A. Brasil , L. G. E. Arruda , A. O. Caldeira

Discordant states appear in a large number of quantum phenomena and seem to be a good indicator of divergence from classicality. While there is evidence that they are essential for a quantum algorithm to have an advantage over a classical…

Quantum Physics · Physics 2013-10-04 Aharon Brodutch

We study bipartite quantum discord as a manifestation of a multipartite entanglement structure in the tripartite purified system. In particular, we find that bipartite quantum discord necessarily manifests itself in the presence of both…

Quantum Physics · Physics 2013-07-29 Eric G. Brown , Eric J. Webster , Eduardo Martin-Martinez , Achim Kempf

Recently, it was realized that quantum discord can be seen as the minimal amount of correlations which are lost when some local quantum operations are performed. Based on this formulation of quantum discord, we provide a systematical…

Quantum Physics · Physics 2011-12-21 Małgorzata Okrasa , Zbigniew Walczak

Quantum systems in mixed states can be unentangled and yet still correlated in a way that is not possible for classical systems. These correlations can be quantified by the quantum discord and might provide a resource for certain…

Quantum Physics · Physics 2014-05-26 B. P. Lanyon , P. Jurcevic , C. Hempel , M. Gessner , V. Vedral , R. Blatt , C. F. Roos

Quantum discord is the quantitative difference between two alternative expressions for bipartite mutual information, given respectively in terms of two distinct definitions for the conditional entropy. By constructing a stochastic model of…

Quantum Physics · Physics 2015-07-22 Vlad Gheorghiu , Marcos C. de Oliveira , Barry C. Sanders

We address the dynamics of nonclassicality for a quantum system interacting with a noisy fluctuating environment described by a classical stochastic field. As a paradigmatic example, we consider a harmonic oscillator initially prepared in a…

Quantum Physics · Physics 2015-10-27 Jacopo Trapani , Matteo Bina , Sabrina Maniscalco , Matteo G. A. Paris

The quantum to classical transition maybe caused by decoherence or by dynamical collapse of the wave-function. We propose quantum discord as a tool, 1) for comparing and contrasting the role of a collapse model (Continuous Spontaneous…

Quantum Physics · Physics 2016-11-14 Shreya Banerjee , Sayantani Bera , Tejinder P. Singh

We investigate the freezing phenomenon of quantum discord occurring in phase damping noise processes. By relating the expression of the time variation of the discord to the convex function of relative entropy, we obtain the necessary and…

Quantum Physics · Physics 2015-03-13 Bo You , Li-Xiang Cen

We address the effect of classical noise on the dynamics of quantum correlations, entanglement and quantum discord, of two non-interacting qubits initially prepared in a Bell state. The effect of noise is modeled by randomizing the…

Quantum Physics · Physics 2013-05-20 Claudia Benedetti , Fabrizio Buscemi , Paolo Bordone , Matteo G. A. Paris

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…

Quantum Physics · Physics 2011-06-28 Aurelian Isar

Quantum decoherence arises due to uncontrollable entanglement between a system with its environment. However the effects of decoherence are often thought of and modeled through a simpler picture in which the role of the environment is to…

Quantum Physics · Physics 2019-09-17 Bing Gu , Ignacio Franco

We study the level surfaces of quantum discord for a class of two-qubit states with parallel nonzero Bloch vectors. The dynamic behavior of quantum discord under decoherence is investigated. It is shown that a class of X states has sudden…

Quantum Physics · Physics 2011-04-12 Bo Li , Zhi-Xi Wang , Shao-Ming Fei

Modern quantum information theory provides new tools for investigating the decoherence-induced "classicality" of open quantum systems. Recent observation that almost all quantum states bear non-classical correlations [A. Ferraro {\it et…

Quantum Physics · Physics 2012-04-17 M. Arsenijevic , J. Jeknic-Dugic , M. Dugic

We investigated the dissipative dynamics of quantum discord for correlated qubits under Markovian environments. The basic idea in the present scheme is that quantum discord is more general, and possibly more robust and fundamental, than…

Quantum Physics · Physics 2015-06-04 M. Mahdian , R. Yousefjani , S. Salimi

Quantum discord, a kind of quantum correlation, is defined as the difference between quantum mutual information and classical correlation in a bipartite system. In general, this correlation is different from entanglement, and quantum…

Quantum Physics · Physics 2015-05-18 Mazhar Ali , A. R. P. Rau , Gernot Alber

The dynamics evolutions of discord and entanglement of two atoms in two independent Lorentzian reservoirs at zero or finite temperature have been investigated by using the time-convolutionless master-equation method. Our results show that,…

Quantum Physics · Physics 2019-05-17 Hong-Mei Zou , Mao-Fa Fang

By starting from the stochastic Hamiltonian of the three correlated spins and modeling their frequency fluctuations as caused by dephasing noisy environments described by Ornstein-Uhlenbeck processes, we study the dynamics of quantum…

Quantum Physics · Physics 2015-06-04 M. Mahdian , R. Yousefjani , S. Salimi