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Related papers: Mutual Uncertainty, Conditional Uncertainty and St…

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We discuss the notions of mutual information and conditional information for noncomposite systems, classical and quantum; both the mutual information and the conditional information are associated with the presence of hidden correlations in…

Quantum Physics · Physics 2017-04-21 Margarita A. Man'ko

We propose a single observable to witness the nonzero quantum discord of an unknown quantum state provided that we have four copies of the state. The expectation value of this observable provides a necessary and sufficient condition for…

Quantum Physics · Physics 2015-05-27 Chengjie Zhang , Sixia Yu , Qing Chen , C. H. Oh

Twin observables, i.e. opposite subsystem observables A+ and A- that are indistinguishable in measurement in a given mixed or pure state W, are investigated in detail algebraicly and geometrically. It is shown that there is a far-reaching…

Quantum Physics · Physics 2021-11-03 F. Herbut , M. Damnjanovic

Most of the fundamental characteristics of quantum mechanics, such as non-locality and contextuality, are manifest in discrete, finite-dimensional systems. However, many quantum information tasks that exploit these properties cannot be…

Quantum Physics · Physics 2022-06-14 Thais L. Silva , Łukasz Rudnicki , Daniel S. Tasca , Stephen P. Walborn

We conjecture a new entropic uncertainty principle governing the entropy of complementary observations made on a system given side information in the form of quantum states, generalizing the entropic uncertainty relation of Maassen and…

Quantum Physics · Physics 2009-07-10 Joseph M. Renes , Jean-Christian Boileau

The notion coexistence of quantum observables was introduced to describe the possibility of measuring two or more observables together. Here we survey the various different formalisations of this notion and their connections. We review…

Quantum Physics · Physics 2011-01-04 P. Busch , J. Kiukas , P. Lahti

We explain several separability criteria which rely on uncertainty relations. For the derivation of these criteria uncertainty relations in terms of variances or entropies can be used. We investigate the strength of the separability…

Quantum Physics · Physics 2009-11-10 Otfried Guehne , Maciej Lewenstein

The notion of entanglement of quantum states is usually defined with respect to a fixed bipartition. Indeed, a global basis change can always map an entangled state to a separable one. The situation is however different when considering a…

Quantum Physics · Physics 2021-06-02 Yu Cai , Baichu Yu , Pooja Jayachandran , Nicolas Brunner , Valerio Scarani , Jean-Daniel Bancal

Coherence of a quantum state intrinsically depends on the choice of the reference basis. A natural question to ask is the following: if we use two or more incompatible reference bases, can~there be some trade-off relation between the…

Quantum Physics · Physics 2016-07-20 Uttam Singh , Arun Kumar Pati , Manabendra Nath Bera

Characterization and certification of nonlocal correlations is one of the the central topics in quantum information theory. In this work, we develop the detection methods of entanglement and steering based on the universal uncertainty…

Quantum Physics · Physics 2017-10-24 Zhih-Ahn Jia , Yu-Chun Wu , Guang-Can Guo

Uncertainty relations capture the essence of the inevitable randomness associated with the outcomes of two incompatible quantum measurements. Recently, Berta et al. have shown that the lower bound on the uncertainties of the measurement…

Quantum Physics · Physics 2012-10-09 Arun Kumar Pati , Mark M. Wilde , A. R. Usha Devi , A. K. Rajagopal , Sudha

We propose a unifying approach to the separability problem using covariance matrices of locally measurable observables. From a practical point of view, our approach leads to strong entanglement criteria that allow to detect the entanglement…

Quantum Physics · Physics 2007-10-04 O. Gühne , P. Hyllus , O. Gittsovich , J. Eisert

The uncertainty associated with probing the quantum state is expressed as the effective abundance (measure) of possibilities for its collapse. New kinds of uncertainty limits entailed by quantum description of the physical system arise in…

Quantum Physics · Physics 2019-07-12 Ivan Horváth , Robert Mendris

Quantum conditional mutual information (QCMI) is a versatile information theoretic measure. It is used to find the amount of correlations between two qubits from the perspective of a third qubit. In this work we characterise the QCMI of…

Quantum Physics · Physics 2024-01-25 H Saveetha , Peter P. Rohde , R Chandrashekar

We investigate the detection of entanglement in $n$-partite quantum states. We obtain practical separability criteria to identify genuinely entangled and non-separable mixed quantum states. No numerical optimization or eigenvalue evaluation…

Quantum Physics · Physics 2010-12-15 Ting Gao , Yan Hong

In this letter we investigate the possibility of observing macroscopic entanglement, considering realistic factors such as decoherence, particle losses, and measurements of limited precision (coarse-grained collective measurements). This…

Quantum Physics · Physics 2025-02-24 Martina Gisti , Miguel Gallego , Borivoje Dakić

In this Letter, we show that the fulfillment of uncertainty relations is a sufficient criterion for a quantum-mechanically permissible state. We specifically construct two pseudo-spin observables for an arbitrary non-positive Hermitian…

Quantum Physics · Physics 2009-11-13 Hyunchul Nha , M. Suhail Zubairy

We derive an exact uncertainty relation for arbitrary quantum states of finite-dimensional Hilbert spaces. For any given $k$-partition of a $d$-dimensional multipartite system, we introduce the total uncertainty as the sum of the…

Quantum Physics · Physics 2026-03-19 G. Tartaglione , G. Zanfardino , F. Illuminati

The well-known Robertson-Schr\"odinger uncertainty relations have state-dependent lower bounds which are trivial for certain states. We present a general approach to deriving tight state-independent uncertainty relations for qubit…

Quantum Physics · Physics 2016-02-26 Alastair A. Abbott , Pierre-Louis Alzieu , Michael J. W. Hall , Cyril Branciard

We investigate the sample complexity of mutual information and conditional mutual information testing. For conditional mutual information testing, given access to independent samples of a triple of random variables $(A, B, C)$ with unknown…

Data Structures and Algorithms · Computer Science 2025-06-05 Jan Seyfried , Sayantan Sen , Marco Tomamichel