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Non-locality is a fundamental trait of quantum many-body systems, both at the level of pure states, as well as at the level of mixed states. Due to non-locality, mixed states of any two subsystems are correlated in a stronger way than what…

Statistical Mechanics · Physics 2016-09-28 Daniele Malpetti , Tommaso Roscilde

We propose a measure of non-classical correlations in bipartite quantum states based on local unitary operations. We prove the measure is non-zero if and only if the quantum discord is non-zero; this is achieved via a new characterization…

Quantum Physics · Physics 2013-06-25 Sevag Gharibian

We explore the conceptual usefulness of Riemannian geometric tools induced by the statistical concept of distinguishability in quantifying the effect of a depolarizing channel on quantum states. Specifically, we compare the geometries of…

Mathematical Physics · Physics 2012-05-01 Carlo Cafaro , Stefano Mancini

The aim of this paper is to suggest a new interpretation of quantum indeterminacy using the notion of polar duality from convex geometry. Our approach does not involve the usual variances and covariances, whose use to describe quantum…

Quantum Physics · Physics 2024-07-10 Maurice de Gosson

An arbitrarily dense discretisation of the Bloch sphere of complex Hilbert states is constructed, where points correspond to bit strings of fixed finite length. Number-theoretic properties of trigonometric functions (not part of the…

Quantum Physics · Physics 2020-03-06 T. N. Palmer

Local available quantum correlations (LAQC), as defined by Mundarain et al., are analyzed for non-symmetric 2-qubit X states, that is, X-states that are not invariant under the exchange of subsystems and therefore have local Bloch vectors…

Quantum Physics · Physics 2023-11-29 David Bellorin , Hermann Albrecht , Douglas F. Mundarain

Quantum correlations are of fundamental importance in quantum phenomena and quantum information processing studies. The measure of quantum correlations is one central issue. The recently proposed measure of quantum correlations, the local…

Quantum Physics · Physics 2015-12-29 Shuhao Wang , Hui Li , Xian Lu , Bin Chen , Gui Lu Long

Quantum resources play crucial roles for displaying superiority in many quantum communication and computation tasks. To reveal the intrinsic relations hidden in these quantum resources, many efforts have been made in recent years. In this…

Quantum Physics · Physics 2019-03-27 Wen-Yang Sun , Dong Wang , Bao-Long Fang , Zhi-Yong Ding , Huan Yang , Fei Ming , Liu Ye

Nonlocality and entanglement are not only the fundamental characteristics of quantum mechanics but also important resources for quantum information and computation applications. Exploiting the quantitative relationship between the two…

Quantum Physics · Physics 2020-04-20 Zhaofeng Su , Haisheng Tan , Xiangyang Li

The quantum marginal problem consists in deciding whether a given set of marginal reductions is compatible with the existence of a global quantum state or not. In this work, we formulate the problem from the perspective of dynamical systems…

Quantum Physics · Physics 2022-09-29 Daniel Uzcátegui Contreras , Dardo Goyeneche

A symmetric measure of quantum correlation based on the Hilbert-Schmidt distance is presented in this paper. For two-qubit states, we simplify considerably the optimization procedure so that numerical evaluation can be performed…

Quantum Physics · Physics 2011-07-18 Mingjun Shi , Fengjian Jiang , Jiangfeng Du

Bloch electrons in multiorbital systems carry quantum geometric information characteristic of their wavevector-dependent interorbital mixing. The geometric nature impacts electromagnetic responses, and this effect carries over to the…

Superconductivity · Physics 2023-07-11 Weipeng Chen , Wen Huang

In contrast to the wide-spread opinion that any separable quantum state satisfies every classical probabilistic constraint, we present a simple example where a separable quantum state does not satisfy the original Bell inequality although…

Quantum Physics · Physics 2007-05-23 Elena R. Loubenets

Quantum correlation includes quantum entanglement and quantum discord. Both entanglement and discord have a common necessary condition--------quantum coherence or quantum superposition. In this paper, we attempt to give an alternative…

Quantum Physics · Physics 2014-09-23 Chang-shui Yu , Yang Zhang , Haiqing Zhao

We employ the concepts of local quantum uncertainty and geometric quantum discord based on the trace norm to investigate the environmental effects on quantum correlations of two bipartite quantum systems. The first one concerns a two-qubit…

Quantum Physics · Physics 2019-04-10 Abdallah Slaoui , Mohammed Daoud , Rachid Ahl Laamara

Recently, an explicit relation between a measure of entanglement and a geometric entity has been reported in Quantum Inf. Process. (2016) 15:1629-1638. It has been shown that if a qubit gets entangled with another ancillary qubit then…

Quantum Physics · Physics 2019-04-10 Pratapaditya Bej , Prasenjit Deb

Using the monotonity of relative entropy of composite quantum systems we obtain new entropic inequalities for arbitrary density matrices of single qudit states. Example of qutrit state inequalities and the "qubit portrait" bound for the…

Quantum Physics · Physics 2019-02-12 V. N. Chernega , O. V. Man'ko , V. I. Man'ko

The Bloch sphere provides an elegant way of visualizing a qubit. Analogous representation of the simplest composite state of two-qubits has attracted significant attention. Here we present a detailed mathematical analysis of the real-matrix…

We enhance our quantitative comprehension of the complexity associated with both time-optimal and time sub-optimal quantum Hamiltonian evolutions that connect arbitrary source and target states on the Bloch sphere, as recently presented in…

Quantum Physics · Physics 2025-05-02 Carlo Cafaro , Emma Clements , Abeer Alanazi

Various inequalities (Boole inequality, Chung-Erd\"os inequality, Frechet inequality) for Kolmogorov (classical) probabilities are considered. Quantum counterparts of these inequalities are introduced, which have an extra `quantum…

Quantum Physics · Physics 2019-03-20 A. Vourdas