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Related papers: Coherence, Asymmetry, and Quantum Macroscopicity

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We show that measurement can recover the quantum coherence of a qubit in a non-Markovian environment. The experimental demonstration in an optical system is provided by comparing the visibilities (and fidelities) of the final states with…

Quantum Physics · Physics 2009-11-13 JinShi Xu , ChuanFeng Li , Ming Gong , XuBo Zou , Lei Chen , Geng Chen , JianShun Tang , GuangCan Guo

The distribution of coherence in multipartite systems in examined. We use a new coherence measure with entropic nature and metric properties, based on the quantum Jensen-Shannon divergence. The metric property allows for the coherence to be…

Quantum Physics · Physics 2016-04-26 R. Chandrashekar , P. Manikandan , J. Segar , Tim Byrnes

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

We analyze quantum coherence generated by non-interacting magnons in a ferromagnetic spin chain described by the isotropic Heisenberg model. The exact expression derived for the reduced density operator of an arbitrary subsystem reveals…

Quantum Physics · Physics 2025-09-23 V. C. Vieira , F. M. de Paula

Quantum measurement not only can destroy coherence but also can create it. Here, we estimate the maximum amount of coherence, one can create under a complete non-selective measurement process. For our analysis, we consider projective as…

Quantum Physics · Physics 2022-03-14 Sanuja D. Mohanty , Gautam Sharma , Sk Sazim , Biswajit Pradhan , Arun K. Pati

We consider the characterization of quantum superposition states beyond the pattern "dead and alive". We propose a measure that is applicable to superpositions of multiple macroscopically distinct states, superpositions with different…

Establishing a notion of the quantum state that applies consistently across space and time could be a crucial step toward formulating a relativistic quantum theory. We give an operational meaning to multipartite quantum states over…

Quantum Physics · Physics 2026-04-14 Seok Hyung Lie , Hyukjoon Kwon

Quantum coherence and distributed correlations among subparties are often considered as separate, although operationally linked to each other, properties of a quantum state. Here, we propose a measure able to quantify the contributions…

Quantum Physics · Physics 2018-12-11 Gian Luca Giorgi , Roberta Zambrini

In the quantitative theory of quantum coherence, the amount of coherence for given states can be meaningfully discussed only when referring to a preferred basis. One of the objections to this quantification is that the amount of coherence…

Quantum Physics · Physics 2024-12-11 Zhi-Xiang Jin , Yuan-Hong Tao , Bing Yu , Shao-Ming Fei

We study quantum steering experiments without assuming that the trusted party can perfectly control their measurement device. Instead, we introduce a scenario in which these measurements are subject to small imprecision. We show that small…

Quantum Physics · Physics 2024-02-19 Armin Tavakoli

Quantum measurement is universal for quantum computation. This universality allows alternative schemes to the traditional three-step organisation of quantum computation: initial state preparation, unitary transformation, measurement. In…

Quantum Physics · Physics 2016-09-08 Simon Perdrix , Philippe Jorrand

We outline different approaches to define and quantify decoherence. We argue that a measure based on a properly defined norm of deviation of the density matrix is appropriate for quantifying decoherence in quantum registers. For a…

Mesoscale and Nanoscale Physics · Physics 2010-10-12 L. Fedichkin , V. Privman

As an analogy of best separable approximation (BSA) in the framework of entanglement theory, here we concentrate on the notion of best incoherent approximation, with application to characterizing and quantifying quantum coherence. From both…

Quantum Physics · Physics 2020-09-16 Yao Yao , Dong Li , C. P. Sun

An exploratory approach to the possibility of analyzing nonorthogonality as a quantifiable property is presented. Three different measures for the nonorthogonality of pure states are introduced, and one of these measures is extended to…

Quantum Physics · Physics 2009-10-31 Oliver Cohen

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

Entanglement and coherence are fundamental properties of quantum systems, promising to power near future quantum technologies, such as quantum computation, quantum communication and quantum metrology. Yet, their quantification, rather than…

For one-dimensional continuous-variable quantum systems such as single-mode quantum optical systems, we give a quantification of the quantumness of such a system's state, {\rho}, by introducing the measure of quantumness, {\Xi}, which works…

Quantum Physics · Physics 2026-03-03 Ole Steuernagel , Hsien-Yi Hsieh , Yi-Ru Chen , Ray-Kuang Lee

Quantum decoherence refers to the phenomenon when the interaction of a quantum system with its environment results in the degradation of quantum coherence. Decoherence is considered to be the most popular mechanism responsible for the…

Quantum Physics · Physics 2026-02-25 Mohd Shoaib Qureshi , Tabish Qureshi

We propose a measure of quantumness based on an addition-then-subtraction operation. We demonstrate how this measure can distinguish between classical and bosonic particles by investigating in detail multi-particle bosonic systems.…

Quantum Physics · Physics 2013-07-10 Su-Yong Lee , Changsuk Noh , Dagomir Kaszlikowski

Quantum coherence is a key element in topical research on quantum resource theories and a primary facilitator for design and implementation of quantum technologies. However, the resourcefulness of quantum coherence is severely restricted by…

Quantum Physics · Physics 2015-06-01 Uttam Singh , Manabendra Nath Bera , Himadri Shekhar Dhar , Arun Kumar Pati