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Related papers: Tight bounds for the quantum discord

200 papers

As quantum technologies move from the issues of principle to those of practice, it is important to understand the limitations on attaining tangible quantum advantages. In the realm of quantum communication, quantum discord captures the…

Quantum Physics · Physics 2012-10-17 Vaibhav Madhok , Animesh Datta

Recent findings suggest, separable states, which are otherwise of no use in entanglement dependent tasks, can also be used in information processing tasks that depend upon the discord type general non classical correlations. In this work,…

Quantum Physics · Physics 2023-07-12 Ajoy Sen , Debasis Sarkar , Amit Bhar

We present a numerical framework for the certification and systematic analysis of the relationship between Bell nonlocality and quantum discord. By determining the minimum discord required for a bipartite state to manifest a specific Bell…

Quantum Physics · Physics 2026-05-06 Robert Okuła , Adrian Misiak , Piotr Mironowicz

We obtain an analytical lower bound of entanglement quantified by concurrence for arbitrary bipartite quantum states. It is shown that our bound is tight for some mixed states and is complementary to the previous known lower bounds. On the…

Quantum Physics · Physics 2009-01-24 Yong-Cheng Ou , Heng Fan , Shao-Ming Fei

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

Quantum discord-breaking channels were previously defined as the local channels that act on subsystem $A$ to produce classical-quantum states across system $AB$. However, unlike entanglement, discord is asymmetric. Here, we characterise the…

Quantum Physics · Physics 2019-08-20 Thao P. Le

The problem of detecting non-classical correlations of states of many qudits is incomparably more involved than in a case of qubits. The reason is that for qubits we have a convenient description of the system by the means of the…

Quantum Physics · Physics 2016-10-27 Krzysztof Rosołek , Marcin Wieśniak , Lukas Knips

In this paper, we present the concept of the one-way unlocalizable quantum discord and investigate its properties. We provide a polygamy inequality for it in tripartite pure quantum system of arbitrary dimension. Several tradeoff relations…

Quantum Physics · Physics 2013-05-30 Zhengjun Xi , Heng Fan , Yongming Li

We investigate how much information about a quantum system can be simultaneously communicated to independent observers, by establishing quantitative limits to bipartite quantum correlations in many-body systems. As recently reported in…

Quantum Physics · Physics 2024-02-09 Davide Girolami , Michele Minervini

Near-term quantum computers are noisy, and therefore must run algorithms with a low circuit depth and qubit count. Here we investigate how noise affects a quantum neural network (QNN) for state discrimination, applicable on near-term…

Quantum Physics · Physics 2021-01-27 Andrew Patterson , Hongxiang Chen , Leonard Wossnig , Simone Severini , Dan Browne , Ivan Rungger

We address the question of the role of quantum correlations beyond entanglement in context of quantum magnetometry. To this end, we study the evolution of the quantum discord, measured by the rescaled discord, of two electron-spin qubits…

Quantum Physics · Physics 2015-06-12 Paweł Mazurek , Katarzyna Roszak , Paweł Horodecki

The geometric quantum discord of a two-qudit state has been studied in many papers, however, its exact analytical value in the explicit form is known only for a general two-qubit state, a general qubit-qudit state and some special families…

Quantum Physics · Physics 2024-09-24 Elena R. Loubenets , Louis Hanotel

The quantum capacity of a noisy quantum channel determines the maximal rate at which we can code reliably over asymptotically many uses of the channel, and it characterizes the channel's ultimate ability to transmit quantum information…

Quantum Physics · Physics 2021-10-26 Xin Wang

The ability to distribute quantum entanglement is a prerequisite for many fundamental tests of quantum theory and numerous quantum information protocols. Two distant parties can increase the amount of entanglement between them by means of…

Quantum Physics · Physics 2012-08-24 T. K. Chuan , J. Maillard , K. Modi , T. Paterek , M. Paternostro , M. Piani

We revisit the upper bound of quantum discord given by the von Neumann entropy of the measured subsystem. Using the Koashi-Winter relation, we obtain a trade-off between the amount of classical correlation and quantum discord in the…

Quantum Physics · Physics 2015-06-03 Zhengjun Xi , Xiao-Ming Lu , Xiaoguang Wang , Yongming Li

Analytic quantifiers of the symmetric quantum discord for two-qubit X type states and block-diagonal states and the symmetric measurement induced nonlocality for any two qubit states are established on the basis of the quantum skew…

Quantum Physics · Physics 2019-03-19 Li-qiang Zhang , Si-ren Yang , Chang-shui Yu

We utilize quantum discord to charecterize the correlation present in Buzek-Hillery quantum copying machine \cite{bh} (not necessarily universal quantum cloning machine). In other words we quantify the correlation present beetween the…

Quantum Physics · Physics 2010-07-14 Indranil Chakrabarty

Top quarks have been recently shown to be a promising system to study quantum information at the highest-energy scale available. The current lines of research mostly discuss topics such as entanglement, Bell nonlocality or quantum…

Quantum Physics · Physics 2023-06-07 Yoav Afik , Juan Ramón Muñoz de Nova

A general state of an $m\otimes n$ system is a classical-quantum state if and only if its associated $A$-correlation matrix (a matrix constructed from the coherence vector of the party $A$, the correlation matrix of the state, and a…

Quantum Physics · Physics 2016-04-19 S. Javad Akhtarshenas , Hamidreza Mohammadi , Saman Karimi , Zahra Azmi

A new measure based on the tripartite information diagram is proposed for identifying quantum discord in tripartite systems. The proposed measure generalizes the mutual information underlying discord from bipartite to tripartite systems,…

Quantum Physics · Physics 2017-11-15 Wei-Ting Lee , Che-Ming Li
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