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Related papers: Coherence non-activating measurement

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Interaction-free measurement is shown to arise from the forward-scattered wave accompanying absorption: a "quantum silhouette" of the absorber. Accordingly, the process is not free of interaction. For a perfect absorber the…

Quantum Physics · Physics 2009-10-31 Tamás Geszti

We characterize minimal measurement setups for validating the quantum coherence of an unknown quantum state. We show that for a $d$-level system, the optimal strategy consists of measuring $d$ orthonormal bases such that each measured basis…

Quantum Physics · Physics 2018-06-27 Claudio Carmeli , Teiko Heinosaari , Sabrina Maniscalco , Jussi Schultz , Alessandro Toigo

In quantum metrology, the parameter estimation accuracy is bounded by quantum Fisher information. In this paper, we present coherence measures in terms of (quantum) Fisher information by directly considering the post-selective non-unitary…

Quantum Physics · Physics 2023-07-06 Deng-hui Yu , Chang-shui Yu

Many theoretical calculations of subtle coherent effects in quantum mechanics do not carefully consider the interface between their calculations and experiment. Calculations for gedanken experiments using initial states not satisfied in…

High Energy Physics - Phenomenology · Physics 2010-11-01 Harry J. Lipkin

Wave packets for the Quantum Non-Linear Oscillator are considered in the Generalized Coherent State framerwork. To first order in the non-linearity parameter the Coherent State behaves very similarly to its classical counterpart. The…

Quantum Physics · Physics 2012-07-12 Subir Ghosh

In the resource theory of coherence, the quantification of quantum-state coherence is an important task. In this regard, the key ingredients are the various coherence monotones (or measures). There are few coherence-monotone classes that…

Quantum Physics · Physics 2024-03-13 Manis Hazra , Debabrata Goswami

The original purpose of measurements is to provide us with information about a previously unknown physical property of the system observed. In the Hilbert space formalism of quantum mechanics, this physical meaning of measurement…

Quantum Physics · Physics 2007-05-23 Holger F. Hofmann , Takayoshi Kobayashi , Akira Furusawa

A novel manifestation of nonlocality of quantum mechanics is presented. It is shown that it is possible to ascertain the existence of an object in a given region of space without interacting with it. The method might have practical…

High Energy Physics - Theory · Physics 2009-10-22 Avshalom C. Elitzur , Lev Vaidman

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 comment on the so-called negative-result experiments (also known as null measurements, interaction-free measurements, and so on) in quantum mechanics (QM), in the light of the new general understanding of the quantum-measurement…

Quantum Physics · Physics 2024-10-10 Kenichi Konishi

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 investigate that no-knowledge measurement-based feedback control is utilized to obtain the estimation precision of the detection efficiency. For the feedback operators that concern us, no-knowledge measurement is the optimal way to…

Quantum Physics · Physics 2019-08-13 Dong Xie , Chunling Xu , Jianyong Chen , Anmin Wang

Quantum coherence and quantum correlations lie in the center of quantum information science, since they both are considered as fundamental reasons for significant features of quantum mechanics different from classical mechanics. We present…

Quantum Physics · Physics 2023-02-14 Zeyang Fan , Yi Peng , Yu-Ran Zhang , Shang Liu , Liang-Zhu Mu , Heng Fan

I demonstrate a simple example of how the time series obtained from searches for ultralight bosonic dark matter (DM), such as the axion, can be used to determine whether it is in a coherent or incoherent quantum state. The example is…

High Energy Physics - Phenomenology · Physics 2022-11-28 David J. E. Marsh

We study the extent to which the outcomes of a quantum measurement can be manipulated by changing the state of the measurement apparatus. The measurement process is modeled as decoherence induced by the experimenter, to gain knowledge about…

Quantum Physics · Physics 2017-11-29 Muzaffar Qadir Lone , Chris Nagele , Brad Weslake , Tim Byrnes

The resource theory of coherence studies the operational value of superpositions in quantum technologies. A key question in this theory concerns the efficiency of manipulation and inter-conversion of the resource. Here we solve this…

A measurement is deemed successful, if one can maximize the information gain by the measurement apparatus. Here, we ask if quantum coherence of the system imposes a limitation on the information gain during quantum measurement. First, we…

Quantum Physics · Physics 2020-04-02 Gautam Sharma , Sk Sazim , Arun Kumar Pati

Quantum coherence, the ability to control the phases in superposition states is a resource, and it is of crucial importance, therefore, to understand how it is consumed in use. It has been suggested that catalytic coherence is possible,…

Quantum Physics · Physics 2018-09-26 Joan A. Vaccaro , Sarah Croke , Stephen M. Barnett

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…

Conditional expectation values of quantum mechanical observables reflect unique non-classical correlations, and are generally sensitive to decoherence. We consider the circumstances under which such sensitivity to decoherence is removed,…

Quantum Physics · Physics 2019-01-25 M. Hamed Mohammady , Alessandro Romito