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Related papers: Creating quantum discord through local generalized…

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Quantum discord witnesses the nonclassicality of quantum states even when there is no entanglement in these quantum states. This type of quantum correlation also has some interesting and significant applications in quantum information…

Quantum Physics · Physics 2015-05-19 Mazhar Ali

We study the dynamics of geometric measure of quantum discord (GMQD) under the influences of two local phase damping noises. Consider the two qubits initially in arbitrary X-states, we find the necessary and sufficient conditions for which…

Quantum Physics · Physics 2015-10-20 Wei Song , Zhuo-Liang Cao

Gaussian quantum discord is a measure of quantum correlations in Gaussian systems. Using Gaussian discord we quantify the quantum correlations of a bipartite entangled state and a separable two-mode mixture of coherent states. We…

Quantum Physics · Physics 2012-08-13 Lars S. Madsen , Adriano Berni , Mikael Lassen , Ulrik L. Andersen

We introduce the discording power of a unitary transformation, which assesses its capability to produce quantum discord, and analyze in detail the generation of discord by relevant classes of two-qubit gates. Our measure is based on the…

Quantum Physics · Physics 2013-01-09 F. Galve , F. Plastina , M. G. A. Paris , R. Zambrini

Calculation of the quantum discord requires to find the minimum of the quantum conditional entropy $S(\rho^{AB}|\{\Pi^B_{k}\})$ over all measurements on the subsystem $B$. In this paper, we provide a simple relation for the conditional…

By quantifying the difference between quantum mutual information through weak measurement performed on a subsystem one is led to the notion of super quantum discord. The super version is also known to be difficult to compute as the quantum…

Quantum Physics · Physics 2024-01-04 Jianming Zhou , Xiaoli Hu , Naihuan Jing

Quantum discord is a measure of non-classical correlations, which are excess correlations inherent in quantum states that cannot be accessed by classical measurements. For multipartite states, the classically accessible correlations can be…

Quantum Physics · Physics 2019-09-18 Mark Bradshaw , Ping Koy Lam , Syed M. Assad

We solve the quantum discord completely as an optimization of certain one variable function for arbitrary two qubit X state. Exact solutions of the quantum discord are obtained for several nontrivial regions of the five parametric space for…

Quantum Physics · Physics 2016-08-31 Naihuan Jing , Bing Yu

We study the dynamics of quantum coherence and quantum correlations in two semiconductor double-dot molecules separated by a distance and indirectly coupled via a transmission line resonator. Dominant dissipation processes are considered.…

Quantum Physics · Physics 2012-05-08 Pei Pei , Chong Li , Jia-Sen Jin , He-Shan Song

Recently, Girolami and Adesso have demonstrated that the calculation of quantum discord for two-qubit case can be viewed as to solve a pair of transcendental equation (Phys. Rev. A, {\bf 83}, 052108(2011)). In present work, we introduce the…

Quantum Physics · Physics 2015-06-03 Xiaohua Wu , Tao Zhou

We extend the quantum discord to continuous variable systems and evaluate Gaussian quantum discord C(\rho) for bipartite Gaussian states. In particular, for squeezed thermal states (STS), we explicitly maximize the extractable information…

Quantum Physics · Physics 2015-05-18 Paolo Giorda , Matteo G. A. Paris

I show that entanglement between two qubits can be generated if the two qubits interact with a common heat bath in thermal equilibrium, but do not interact directly with each other. In most situations the entanglement is created for a very…

Quantum Physics · Physics 2009-11-07 Daniel Braun

The evolution of pairwise quantum correlations of Bell cat-states under amplitude damping is examined using the concept of quantum discord which goes beyond entanglement. A closed expression of the quantum discord is explicitly derived. We…

Quantum Physics · Physics 2015-06-11 M. Daoud , R. Ahl Laamara

The qubit (or a system of two quantum dots) has become a standard paradigm for studying quantum information processes. Our focus is Decoherence due to interaction of the qubit with its environment, leading to noise. We consider quantum…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 Ebad Kamil , Sushanta Dattagupta

Quantum discord in a bipartite system can be dynamically revealed and quantified through purely local operations on one of the two subsystems. To achieve this, the local detection method harnesses the influence of initial correlations on…

Quantum Physics · Physics 2017-07-04 Manuel Gessner , Heinz-Peter Breuer , Andreas Buchleitner

In quantum mechanics, observing is not a passive act. Consider a system of two quantum particles A and B: if a measurement apparatus M is used to make an observation on B, the overall state of the system AB will typically be altered. When…

Quantum Physics · Physics 2014-04-09 Gerardo Adesso , Vincenzo D'Ambrosio , Eleonora Nagali , Marco Piani , Fabio Sciarrino

When quantum information is spread over a system through nonclassical correlation, it makes retrieving information by local measurements difficult---making global measurement necessary for optimal parameter estimation. In this paper, we…

Quantum Physics · Physics 2018-07-13 Akira Sone , Quntao Zhuang , Paola Cappellaro

We investigate the creation of entanglement between two quantum emitters interacting with a realistic common stationary electromagnetic field out of thermal equilibrium. In the case of two qubits we show that the absence of equilibrium…

Quantum Physics · Physics 2014-12-15 Bruno Bellomo , Mauro Antezza

Quantum discord has been shown to be a resource for quantum advantage in addition to quantum entanglement. While many experiments have demonstrated classical analogies of entanglement, none have done so for discord. We present a…

The quantum discord is used as measure of quantum correlations for two families of multipartite coherent states. The first family interpolates between generalized GHZ states and generalized Werner states. The second one is an interpolation…

Quantum Physics · Physics 2012-11-01 M. Daoud , R. Ahl Laamara