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Related papers: Coherence, Asymmetry, and Quantum Macroscopicity

200 papers

The existence of incompatible measurements, epitomized by Heisenberg's uncertainty principle, is one of the distinctive features of quantum theory. So far, quantum incompatibility has been studied for measurements that test the preparation…

Quantum Physics · Physics 2017-03-16 Michal Sedlak , Daniel Reitzner , Giulio Chiribella , Mario Ziman

We provide a coherence-based approach to nonclassical behavior by means of distance measures. We develop a quantitative relation between coherence and nonclassicality quantifiers, which establish the nonclassicality as the maximum…

Quantum Physics · Physics 2022-07-20 Laura Ares , Alfredo Luis

In this article, we study quantum coherence of bipartite state from the perspective of weak measurement, which generalizes the notion of coherence relative to measurement. The is being illustrated by computing coherence for the well-known…

Quantum Physics · Physics 2023-04-06 Indrajith V. S , R. Muthuganesan , R. Sankaranarayanan

When quantum systems interact with the environment they lose their quantum properties, such as coherence. Quantum erasure makes it possible to restore coherence in a system by measuring its environment, but accessing the whole of it may be…

Quantum Physics · Physics 2015-12-23 Filippo M. Miatto , Kevin Piché , Thomas Brougham , Robert W. Boyd

Quantum coherence is the outcome of the superposition principle. Recently, it has been theorized as a quantum resource, and is the premise of quantum correlations in multipartite systems. It is therefore interesting to study the coherence…

Quantum Physics · Physics 2017-02-21 Asutosh Kumar

A multi-slit interference experiment, with which-way detectors, in the presence of environment induced decoherence, is theoretically analyzed. The effect of environment is modeled via a coupling to a bath of harmonic oscillators. Through an…

Quantum Physics · Physics 2018-11-02 Anu Venugopalan , Sandeep Mishra , Tabish Qureshi

Quantum coherence is important in quantum mechanics, and its essence is from superposition principle. We study the coherence of any two pure states and that of their arbitrary superposition, and obtain the relationship between them. In the…

Quantum Physics · Physics 2016-05-25 Qiu-Ling Yue , Chao-Hua Yu , Feng Liu , Xiao-Li Wang , Fei Gao , Qiao-Yan Wen

We study the compatibility (or joint measurability) of quantum observables in a setting where the experimenter has access to multiple copies of a given quantum system, rather than performing the experiments on each individual copy…

Quantum Physics · Physics 2016-09-14 Claudio Carmeli , Teiko Heinosaari , Daniel Reitzner , Jussi Schultz , Alessandro Toigo

The effects of the measurement apparatus on quantum coherence are studied by considering a purely dephasing model of a qubit. The initial state is prepared from a thermal state of the whole system by performing a nonselective measurement on…

Quantum Physics · Physics 2021-12-22 Filippo Giraldi

We introduce a measure of average dimensionality (or coherence) for high-dimensional quantum devices. This includes sets of quantum measurements, steering assemblages, and quantum channels. For measurements and channels, our measure…

Quantum Physics · Physics 2023-06-22 Thomas Cope , Roope Uola

There are many striking phenomena which are attributed to ``quantum coherence''. It is natural to wonder if there are new quantum coherence effects waiting to be discovered which could lead to interesting results and perhaps even practical…

High Energy Physics - Theory · Physics 2009-10-28 Andreas Albrecht

We introduce a quantity called the coherence of purification which can be a measure of total quantumness for a single system. We prove that coherence of purification is always more than the coherence of the system. For a pure state, the…

Quantum Physics · Physics 2019-07-31 Arun Kumar Pati , Long-Mei Yang , Chiranjib Mukhopadhyay , Shao-Ming Fei , Zhi-Xi Wang

We reexamine quantum correlation from the fundamental perspective of its consanguineous quantum property, the coherence. We emphasize the importance of specifying the tensor product structure of the total state space before discussing…

Quantum Physics · Physics 2011-04-01 Pei Pei , Wei Wang , Chong Li , He-Shan Song

We consider fundamental limits on the detectable size of macroscopic quantum superpositions. We argue that a full quantum mechanical treatment of system plus measurement device is required, and that a (classical) reference frame for phase…

Quantum Physics · Physics 2017-11-27 M. Skotiniotis , W. Dür , P. Sekatski

The review considers the peculiarities of symmetry breaking and symmetry transformations and the related physical effects in finite quantum systems. Some types of symmetry in finite systems can be broken only asymptotically. However, with a…

Mesoscale and Nanoscale Physics · Physics 2015-06-16 J. L. Birman , R. G. Nazmitdinov , V. I. Yukalov

We demonstrate the simple and deep equivalence between quantum coherence and nonclassicality and the definite way in which they determine metrological resolution. Moreover, we define a coherence observable consistent with a classical…

Quantum Physics · Physics 2021-09-10 Laura Ares , Alfredo Luis

Quantum coherence is a central ingredient in quantum physics with several theoretical and technological ramifications. In this work we consider a figure of merit encoding the information on how the coherence generated on average by a…

Quantum metrology offers an enhanced performance in experiments such as gravitational wave-detection, magnetometry or atomic clocks frequency calibration. The enhancement, however, requires a delicate tuning of relevant quantum features…

Quantum Physics · Physics 2013-07-25 Jan Kolodynski , Rafal Demkowicz-Dobrzanski

This paper examines the coherence in multipartite systems. We first discuss the distribution of total coherence in a given multipartite quantum state into discord between subsystems and coherent dissonance in each individual subsystem,…

Quantum Physics · Physics 2018-09-26 Zhengjun Xi

Coherence is a familiar concept in physics: It is the driving force behind wavelike phenomena such as the diffraction of light. Moreover, wave-particle duality implies that all quantum objects can exhibit coherence, and this quantum…

Quantum Physics · Physics 2009-11-11 Brendon W. Lovett , Ahsan Nazir