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Related papers: Quantum discord and the power of one qubit

200 papers

We revisit the problem of the dynamics of quantum correlations in the exact Tavis-Cummings model. We show that many of the dynamical features of quantum discord attributed to dissipation are already present in the exact framework and are…

Quantum Physics · Physics 2016-06-22 Juliana Restrepo , Boris A. Rodriguez

We study the quantum discord (QD) and the classical correlations (CC) in a reference model for strongly correlated electrons, the one-dimensional bond-charge extended Hubbard model. We show that the comparison of QD and CC and of their…

Quantum Physics · Physics 2013-05-29 Michele Allegra , Paolo Giorda , Arianna Montorsi

We have analytically calculated the quantum discord for a system composed of spin-$j$ and spin-1/2 subsystems possessing SU(2) symmetry. We have compared our results with the quantum discord of states having similar symmetries and seen that…

Quantum Physics · Physics 2013-11-05 B. Çakmak , Z. Gedik

We consider the role of quantum correlations in the efficient use of information by a predictive quantum system, generalizing a recently proposed classical measure of non-predictive information to the quantum regime. We show that, as a…

Quantum Physics · Physics 2014-08-27 Arne L. Grimsmo

A major signature of quantum mechanics beyond classical physics is coherence, the existence of superposition states. The recently developed resource theory of quantum coherence allows the formalisation of incoherent operations -- those…

Quantum Physics · Physics 2016-11-10 Benjamin Yadin , Jiajun Ma , Davide Girolami , Mile Gu , Vlatko Vedral

Positivity of quantum discord is shown to be equivalent to the strong sub additivity of the Von-Nuemann entropy. This leads to a connection between the mother protocol of quantum information theory [A. Abeyesinghe, I. Devetak, P. Hayden,…

Quantum Physics · Physics 2011-07-07 Vaibhav Madhok , Animesh Datta

We focus our attention on two-qubit mixed states as initial states, and apply the geometric measure of quantum discord to investigate quantum discord properties in the background of a Schwarzschild black hole under phase damping, phase flip…

Quantum Physics · Physics 2026-04-08 Yuxuan Xiong , Zhiling Pi , Tinggui Zhang , Xiaofen Huang

We build a machine learning model to detect correlations in a three-qubit system using a neural network trained in an unsupervised manner on randomly generated states. The network is forced to recognize separable states, and correlated…

Quantum Physics · Physics 2024-08-20 Mateusz Krawczyk , Jarosław Pawłowski , Maciej M. Maśka , Katarzyna Roszak

We review the theoretical and the experimental aspects regarding the quantification and identification of quantum correlations in liquid-state nuclear magnetic resonance (NMR) systems at room temperature. We start by introducing a formal…

We study the dynamics of quantum discord and entanglement for two spin qubits coupled to a spin chain with Dzyaloshinsky-Moriya (DM) interaction. We numerically and analytically investigate the time evolution of quantum discord and…

Quantum Physics · Physics 2011-09-27 Yi-ying Yan , Li-jun Tian , Li-guo Qin

We address the experimental determination of entropic quantum discord for systems made of a pair of polarization qubits. We compare results from full and partial tomography and found that the two determinations are statistically compatible,…

Entangled quantum states are regarded as a key resource in quantum key distribution (QKD) protocols. However, quantum correlations, other than entanglement can also play a significant role in the QKD protocols. In this work, we will focus…

Quantum Physics · Physics 2025-12-09 Rashi Jain , Satyabrata Adhikari

In this paper we present a new unified theoretical framework that describes the full dynamics of quantum computation. Our formulation allows any questions pertaining to the physical behavior of a quantum computer to be framed, and in…

Quantum Physics · Physics 2007-05-23 Gerald Gilbert , Michael Hamrick , F. Javier Thayer

Quantum entanglement is the most popular kind of quantum correlations, and its fundamental role in several tasks in quantum information theory like quantum cryptography, quantum dense coding, and quantum teleportation is undeniable.…

Quantum Physics · Physics 2014-11-13 Alexander Streltsov

The dynamics of the quantum discord for two identical qubits in both two independent single-mode cavities and a common single-mode cavity are discussed. For the initial Bell state with correlated spins, while the entanglement sudden death…

Quantum Physics · Physics 2015-06-04 Chen Wang , Qing-Hu Chen

Weak measurement is a new way to manipulate and control quantum systems. Different from projection measurement, weak measurement only makes a small change in status. Applying weak measurement to quantum discord, Singh and Pati proposed a…

Quantum Physics · Physics 2015-02-16 Tao Li , Teng Ma , Yaokun Wang , Shaoming Fei , Zhixi Wang

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

One of the best signatures of nonclassicality in a quantum system is the existence of correlations that have no classical counterpart. Different methods for quantifying the quantum and classical parts of correlations are amongst the more…

Quantum Physics · Physics 2012-11-29 Kavan Modi , Aharon Brodutch , Hugo Cable , Tomasz Paterek , Vlatko Vedral

We report a study on the zero-temperature quantum discord as a measure of two-spin correlation of a transverse XY spin chain following a quench across a quantum critical point and investigate the behavior of mutual information, classical…

Statistical Mechanics · Physics 2021-02-15 Tanay Nag , Ayoti Patra , Amit Dutta

The discovery of the intriguing phenomenon that certain kinds of quantum correlations remain impervious to noise up to a specific point in time and then suddenly decay, has generated immense recent interest. We exploit dynamical decoupling…

Quantum Physics · Physics 2018-02-14 Harpreet Singh , Arvind , Kavita Dorai