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Related papers: Revisiting Quantum discord for two-qubit X states:…

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The concept of entropy and the correct application of the Second Law of thermodynamics are essential in order to understand the reason why quantum error correction is thermodynamically possible and no violation of the Second Law occurs…

Quantum Physics · Physics 2015-06-16 Carlo Cafaro , Peter van Loock

Most previous efforts of quantum error correction focused on either extending classical error correction schemes to the quantum regime by performing a perfect correction on a subset of errors, or seeking a recovery operation to maximize the…

Quantum Physics · Physics 2023-09-06 Chengjie Zhang , Liangsheng Li , Guodong Lu , Haidong Yuan , Runyao Duan

The original definition of quantum discord of bipartite states was defined over one-sided projective measurements, it describes quantum correlation more extensively than entanglement. Dakic, Vedral, and Brukner [Phys. Rev. Lett. 105 (2010)…

Quantum Physics · Physics 2015-05-27 Jianwei Xu

Quantum discord represents a correlation beyond classicality that could be useful for many quantum information tasks, and therefore is viewed as a valuable quantum resource. Theoretically, whether a bipartite quantum state has a non-zero…

Quantum Physics · Physics 2025-06-10 Rong Wang , Yao Yao , Zhen-Qiang Yin

We study the fundamental limits on the reliable storage of quantum information in lattices of qubits by deriving tradeoff bounds for approximate quantum error correcting codes. We introduce a notion of local approximate correctability and…

Quantum Physics · Physics 2021-10-26 Steven T. Flammia , Jeongwan Haah , Michael J. Kastoryano , Isaac H. Kim

In relation of observable and quantum state, the entity $I_C$ from previous work quantifies simultaneously coherence, incompatibility and quantumness. In this article its application to quantum correlations in bipartite states is studied.…

Quantum Physics · Physics 2007-05-23 Fedor Herbut

The hopes for scalable quantum computing rely on the "threshold theorem": once the error per qubit per gate is below a certain value, the methods of quantum error correction allow indefinitely long quantum computations. The proof is based…

Quantum Physics · Physics 2014-01-17 M. I. Dyakonov

We derive analytical formula for the optimal trade-off between the mean estimation fidelity and the mean fidelity of the qubit state after a partial measurement on N identically prepared qubits. We also conjecture analytical expression for…

Quantum Physics · Physics 2009-11-13 Ladislav Mista , Jaromir Fiurasek

We address the issue of reducing the resource required to compute information-theoretic quantum correlation measures like quantum discord and quantum work deficit in two qubits and higher dimensional systems. We show that determination of…

Quantum Physics · Physics 2015-12-18 Titas Chanda , Tamoghna Das , Debasis Sadhukhan , Amit Kumar Pal , Aditi Sen De , Ujjwal Sen

The performance of quantum computers today can be studied by analyzing the effect of errors in the result of simple quantum algorithms. The modeling and characterization of these errors is relevant to correct them, for example, with quantum…

Quantum Physics · Physics 2019-12-17 Efrain Buksman , Andr/'e L. Fonseca de Oliveira , Carolina Allende

The quantumness of a generic state is the resource of many applications in quantum information theory and it is interesting to survey the measures which are able to detect its trace in the properties of the state. In this work we study the…

Quantum Physics · Physics 2016-04-26 Javad Behdani , Seyed Javad Akhtarshenas , Mohsen Sarbishaei

Quantum discord quantifies non-classical correlations in quantum states. We introduce discord for states in causal probabilistic theories, inspired by the original definition proposed in Ref. [17]. We show that the only probabilistic theory…

Quantum Physics · Physics 2012-09-13 Paolo Perinotti

In this article, we investigate the geometric discord of quantum states of fermionic system in accelerated frame. It is shown by the method beyond the single-mode approximation, depending on the region considered, that the geometric discord…

Quantum Physics · Physics 2012-10-12 Jinho Chang , L. C. Kwek , Younghun Kwon

We investigate the impact of a symmetric quantum feedback control on the quantum discord of the X state in V-shaped plasmonic waveguides. Under this feedback, the quantum discord of the Werner state is enhanced from 0 to 0.38. This value…

Quantum Physics · Physics 2025-07-22 Hua-Wei Zhao , Gen Li , Guo-Feng Zhang

A fundamental problem in quantum information is to explore what kind of quantum correlations is responsible for successful completion of a quantum information procedure. Here we study the roles of entanglement, discord, and dissonance…

Quantum Physics · Physics 2015-03-20 Fu-Lin Zhang , Jing-Ling Chen , L. C. Kwek , Vlatko Vedral

We consider 1-qubit mixed quantum state estimation by adaptively updating measurements according to previously obtained outcomes and measurement settings. Updates are determined by the average-variance-optimality (A-optimality) criterion,…

Quantum Physics · Physics 2012-05-21 Takanori Sugiyama , Peter S. Turner , Mio Murao

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

In this MSc thesis I consider the asymptotic behaviour of the symmetric error in composite hypothesis testing. In the classical case, when the null and alternative hypothesis are finite sets of states, the best achievable symmetric error…

Quantum Physics · Physics 2020-11-09 Zsombor Szilágyi

The error threshold for fault tolerant quantum computation with concatenated encoding of qubits is penalized by internal communication overhead. Many quantum computation proposals rely on nearest-neighbour communication, which requires…

Quantum Physics · Physics 2007-05-23 T. Szkopek , P. O. Boykin , H. Fan , V. Roychowdhury , E. Yablonovitch , G. Simms , M. Gyure , B. Fong

Geometric discord, a measure of quantumness of bipartite system, captures minimal nonlocal effects of a quantum state due to locally invariant von Neumann projective measurements. Original version of this measure is suffered by the local…

Quantum Physics · Physics 2019-06-10 R. Muthuganesan , V. K. Chandrasekar
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