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Related papers: Witnessing Quantum Coherence: from solid-state to …

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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

Quantum processes, such as quantum circuits, quantum memories, and quantum channels, are essential ingredients in almost all quantum information processing tasks. However, the characterization of these processes remains a daunting task due…

Quantum Physics · Physics 2020-04-16 Ye-Chao Liu , Jiangwei Shang , Xiao-Dong Yu , Xiangdong Zhang

The characterization of quantum coherence in the context of quantum information theory and its interplay with quantum correlations is currently subject of intense study. Coherence in an Hamiltonian eigenbasis yields asymmetry, the ability…

Quantum Physics · Physics 2017-03-24 Davide Girolami , Benjamin Yadin

We demonstrate the first violation of the Leggett-Garg inequality and time-order noninvariance on public quantum computers using genuine noninvasive measurements. By gathering sufficiently large statistics, we have been able to violate…

The quantification of quantum correlations (other than entanglement) usually entails laboured numerical optimization procedures also demanding quantum state tomographic methods. Thus it is interesting to have a laboratory friendly witness…

The task of testing whether quantum theory applies to all physical systems and all scales requires considering situations where a quantum probe interacts with another system that need not obey quantum theory in full. Important examples…

Quantum Physics · Physics 2020-03-04 Gaurav Bhole , Jonathan A. Jones , Chiara Marletto , Vlatko Vedral

In view of the tomographic-probability representation of quantum states, we reconsider the approach to quantumness tests of a single system developed in [Alicki and Van Ryn 2008 J. Phys. A: Math. Theor. 41 062001]. For qubits we introduce a…

Quantum Physics · Physics 2009-05-01 S. N. Filippov , V. I. Man'ko

Quantum coherence, the ability of a quantum system to be in a superposition of orthogonal quantum states, is a distinct feature of the quantum mechanics, thus marking a deviation from classical physics. Coherence finds its applications in…

Quantum Physics · Physics 2023-01-18 Najmeh Etehadi Abari , Andrey Rakhubovsky , Radim Filip

We propose a new Wigner inequality suitable for test of the hypothesis of realism. We show that this inequality is not identical neither to the well-known Wigner inequality nor to the Leggett-Garg inequality in Wigner form. The obtained…

Quantum Physics · Physics 2019-12-18 N. Nikitin , K. Toms

There are not many tools to quantitatively monitor the emergence of classical geometric features from a quantum spacetime, whose microscopic structure may be a highly quantum-fluctuating "spacetime foam". To improve this situation, we…

High Energy Physics - Theory · Physics 2023-05-10 R. Loll , A. Silva

Quantum coherence quantifies the amount of superposition in a quantum system, and is the reason and resource behind several phenomena and technologies. It depends on the natural basis in which the quantum state of the system is expressed,…

Quantum Physics · Physics 2021-08-13 Ingita Banerjee , Kornikar Sen , Chirag Srivastava , Ujjwal Sen

Quantum coherence, the physical property underlying fundamental phenomena such as multi-particle interference and entanglement, has emerged as a valuable resource upon which modern technologies are founded. In general, the most prominent…

Developments in the foundations of quantum mechanics have identified several attributes and tests associated with the "quantumness" of systems, including entanglement, nonlocality, quantum erasure, Bell test, etc. Here we introduce and…

Quantum Physics · Physics 2016-05-03 Torsten Scholak , Paul Brumer

We introduce a procedure based on quantum expectation values of measurement observables to characterize quantum coherence. Our measure allows one to quantify coherence without having to perform tomography of the quantum state, and can be…

Quantum coherence generated in a physical process can only be cast as a potentially useful resource if its effects can be detected at a later time. Recently, the notion of non-coherence-generating-and-detecting (NCGD) dynamics has been…

As a quantum resource, quantum coherence plays an important role in modern physics. Many coherence measures and their relations with entanglement have been proposed, and the dynamics of entanglement has been experimentally studied. However,…

Quantum Physics · Physics 2023-07-18 Yi Zheng , Cheng-Jie Zhang , Zheng-Hao Liu , Jian-Wei Shao , Jin-Shi Xu , Chuan-Feng Li , Guang-Can Guo

It is shown that quantum-type coherence, leading to indeterminism and interference of probabilities, may in principle exist in the absence of the Planck constant and a Hamiltonian. Such coherence is a combined effect of a symmetry (not…

Quantum Physics · Physics 2007-05-23 Y. Orlov

Quantum coherence and non-classical correlation are key features of quantum world. Quantifying coherence and non-classical correlation are two key tasks in quantum information theory. First, we present a bona fide measure of quantum…

Quantum Physics · Physics 2018-06-29 Zhi-Xiang Jin , Shao-Ming Fei

The detection and certification of entanglement and quantum correlations in materials is of fundamental and far-reaching importance, and has seen significant recent progress. It impacts both our understanding of the basic science of quantum…

Quantum Physics · Physics 2025-03-31 Pontus Laurell , Allen Scheie , Elbio Dagotto , D. Alan Tennant

It has been experimentally demonstrated that quantum coherence can persist in macroscopic phenomena [J.R. Friedman et al.,Nature, 406 (2000) 43]. To face the challenge of this new fact, in this article QM in its standard form is assumed to…

Quantum Physics · Physics 2007-05-23 F. Herbut