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Related papers: Computing quantum discord is NP-complete

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Integer programming (IP) is an NP-hard combinatorial optimization problem that is widely used to represent a diverse set of real-world problems spanning multiple fields, such as finance, engineering, logistics, and operations research. It…

Quantum Physics · Physics 2025-08-20 Kapil Goswami , Peter Schmelcher , Rick Mukherjee

We describe an efficient DQC1-algorithm to quantify the amount of Geometric Quantum Discord present in the output state of a DQC1 computation. DQC1 is a model of computation that utilizes separable states to solve a problem with no known…

Quantum Physics · Physics 2012-07-13 G. Passante , O. Moussa , R. Laflamme

One advantage of quantum algorithms over classical computation is the possibility to spread out, process, analyse and extract information in multipartite configurations in coherent superpositions of classical states. This will be discussed…

Quantum Physics · Physics 2007-05-23 Karl Svozil

The quantum computer is supposed to process information by applying unitary transformations to the complex amplitudes defining the state of N qubits. A useful machine needing N=1000 or more, the number of continuous parameters describing…

Quantum Physics · Physics 2014-09-23 M. I. Dyakonov

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 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

Entanglement is known to be an essential resource for many quantum information processes. However, it is now known that some quantum features may be acheived with quantum discord, a generalized measure of quantum correlation. In this paper,…

Quantum correlations characterized by quantum entanglement and quantum discord play important roles in many quantum information processing. We study the relations among the entanglement of formation, concurrence, tangle, linear entropy…

Quantum Physics · Physics 2018-08-03 Xue-Na Zhu , Shao-Ming Fei , Xianqing Li-Jost

We show that approximating the trace norm contraction coefficient of a quantum channel within a constant factor is NP-hard. Equivalently, this shows that determining the optimal success probability for encoding a bit in a quantum system…

Quantum Physics · Physics 2025-09-23 Idris Delsol , Omar Fawzi , Jan Kochanowski , Akshay Ramachandran

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,…

Computational complexity is examined using the principle of increasing entropy. To consider computation as a physical process from an initial instance to the final acceptance is motivated because many natural processes have been recognized…

Computational Complexity · Computer Science 2012-03-20 Arto Annila

NP-hard problems are not believed to be exactly solvable through general polynomial time algorithms. Hybrid quantum-classical algorithms to address such combinatorial problems have been of great interest in the past few years. Such…

Quantum Physics · Physics 2024-01-15 Yagnik Chatterjee , Eric Bourreau , Marko J. Rančić

The quantum discord of bipartite systems is one of the best-known measures of non-classical correlations and an important quantum resource. In the recent work appeared in [Phys. Rev. Lett 2020, 124:110401], the quantum discord has been…

Quantum Physics · Physics 2022-05-16 Jianming Zhou , Xiaoli Hu , Naihuan Jing

Scientists have demonstrated that quantum computing has presented novel approaches to address computational challenges, each varying in complexity. Adapting problem-solving strategies is crucial to harness the full potential of quantum…

Computational Complexity · Computer Science 2024-09-13 Arash Vaezi , Ali Movaghar , Mohammad Ghodsi , Seyed Mohammad Hussein Kazemi , Negin Bagheri Noghrehy , Seyed Mohsen Kazemi

Coherence and entanglement are fundamental properties of quantum systems, promising to power the near future quantum computers, sensors and simulators. Yet, their experimental detection is challenging, usually requiring full reconstruction…

Quantum Physics · Physics 2017-08-01 Graeme Smith , John A. Smolin , Xiao Yuan , Qi Zhao , Davide Girolami , Xiongfeng Ma

The topical quantum computation paradigm is a transposition of the Turing machine into the quantum framework. Implementations based on this paradigm have limitations as to the number of: qubits, computation steps, efficient quantum…

Quantum Physics · Physics 2007-05-23 Giuseppe Castagnoli

Here, we show that partial transposition, which is initially introduced to study entanglement, can also inspire many results on quantum discord including: (I) a discord criterion of spectrum invariant under partial transposition, stating…

Quantum Physics · Physics 2023-05-17 Sun Liang-Liang , Zhou Xiang , Yu Sixia

We investigate quantum states that posses both maximum entanglement and maximum discord between the pertinent parties. Since entanglement (discord) is defined only for bipartite (two qubit) systems, we shall introduce an appropriate sum…

Quantum Physics · Physics 2013-03-27 J. Batle , M. Casas , A. Plastino

For any bipartite state, how strongly can one subsystem be quantum correlated with another? Using the Koashi-Winter relation, we study the upper bound of purified quantum discord, which is given by the sum of the von Neumann entropy of the…

Quantum Physics · Physics 2014-11-17 Feng Liu , Guo-Jing Tian , Su-Juan Qin , Qiao-Yan Wen , Fei Gao

The simple and universal global optimization method based on simplified multipopulation genetic algorithm is presented. The method is applied to quantum information problems. It is compared to the genetic algorithm on standard test…

Quantum Physics · Physics 2013-04-15 A. Yu. Chernyavskiy