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Related papers: Exact Steering Bound for Two-Qubit Werner States

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We derive a measurement operator corresponding to a quantum nondemolition (QND) measurement of an atomic ensemble. The quantum measurement operator takes the form of a positive operator valued measure (POVM) and is valid for arbitrary…

While continuous-variable (CV) quantum systems are believed to be more efficient for quantum sensing and metrology than their discrete-variable (DV) counterparts due to the infinite spectrum of their native operators, our toolkit of…

Quantum Physics · Physics 2025-01-10 Xi Lu , Bojko N. Bakalov , Yuan Liu

For a class of positive operator valued measures, we introduce the spectral gap, an invariant which shows up in a number of contexts: the quantum noise operator responsible for the unsharpness of quantum measurements, the Markov chain…

Mathematical Physics · Physics 2018-11-12 Victoria Kaminker , Leonid Polterovich , Dor Shmoish

We consider group-covariant positive operator valued measures (POVMs) on a finite dimensional quantum system. Following Neumark's theorem a POVM can be implemented by an orthogonal measurement on a larger system. Accordingly, our goal is to…

Quantum Physics · Physics 2023-11-27 Thomas Decker , Dominik Janzing , Martin Roetteler

Many quantum measurements, such as photodetection, can be destructive. In photodetection, when the detector clicks a photon has been absorbed and destroyed. Yet the lack of a click also gives information about the presence or absence of a…

Quantum Physics · Physics 2019-07-02 Yi-Hsiang Chen , Todd A. Brun

The most general type of measurement in quantum physics is modeled by a positive operator-valued measure (POVM). Mathematically, a POVM is a generalization of a measure, whose values are not real numbers, but positive operators on a Hilbert…

Logic in Computer Science · Computer Science 2014-12-31 Frank Roumen

Measurement correlations in quantum systems can exhibit non-local behavior, a fundamental aspect of quantum mechanics with applications such as device-independent quantum information processing. However, the explicit construction of local…

Quantum Physics · Physics 2025-04-30 Nick von Selzam , Florian Marquardt

The purpose of quantum tomography is to determine an unknown quantum state from measurement outcome statistics. There are two obvious ways to generalize this setting. First, our task need not be the determination of any possible input state…

Quantum Physics · Physics 2014-02-11 Claudio Carmeli , Teiko Heinosaari , Jussi Schultz , Alessandro Toigo

Einstein-Podolsky-Rosen steering refers to the quantum phenomenon whereby the state of a system held by one party can be "steered" into different states at the will of another, distant, party by performing different local measurements.…

Quantum Physics · Physics 2019-06-12 Travis J. Baker , Sabine Wollmann , Geoff J. Pryde , Howard M. Wiseman

We introduce and implement a technique to extend the quantum computational power of cluster states by replacing some projective measurements with generalized quantum measurements (POVMs). As an experimental demonstration we fully realize an…

Among certification techniques, those based on the violation of Bell inequalities are appealing because they do not require assumptions on the underlying Hilbert space dimension and on the accuracy of calibration methods. Such…

Quantum Physics · Physics 2020-03-20 Sebastian Wagner , Jean-Daniel Bancal , Nicolas Sangouard , Pavel Sekatski

Quantum measurements are ubiquitous in quantum information processing tasks, but errors can render their outputs unreliable. Here, we present a scheme that implements a robust projective measurement through measuring code-inspired…

Quantum Physics · Physics 2024-11-11 Yingkai Ouyang

We investigate the problem of bounding the quantum process fidelity given bounds on the fidelities between target states and the action of a process on a set of pure input states. We formulate the problem as a semidefinite program and prove…

Quantum Physics · Physics 2018-11-28 Karl Mayer , Emanuel Knill

We investigate the measurement uncertainties of a triple of positive operator-valued measures (POVMs) based on statistical distance, and formulate state-independent tight uncertainty inequalities satisfied by the three measurements in terms…

Quantum Physics · Physics 2019-03-13 Hui-Hui Qin , Ting-Gui Zhang , Leonardo Jost , Chang-Pu Sun , Xianqing Li-Jost , Shao-Ming Fei

Generalized measurements, also called positive operator-valued measures (POVMs), can offer advantages over projective measurements in various quantum information tasks. Here, we realize a generalized measurement of one and two…

Quantum Physics · Physics 2024-08-27 Petr Ivashkov , Gideon Uchehara , Liang Jiang , Derek S. Wang , Alireza Seif

We show that a one-dimensional discrete time quantum walk can be used to implement a generalized measurement in terms of positive operator value measure (POVM) on a single qubit. More precisely, we show that for a single qubit any set of…

Quantum Physics · Physics 2013-05-22 Pawel Kurzynski , Antoni Wojcik

We give an overview of joint unsharp measurements of non-commuting observables using positive operator valued measures (POVMs). We exemplify the role played by joint measurability of POVMs in entropic uncertainty relation for Alice's pair…

Quantum Physics · Physics 2015-05-19 H. S. Karthik , A. R. Usha Devi , A. K. Rajagopal

We introduce positive operator-valued measure (POVM) generated by the projective unitary representation of a direct product of locally compact Abelian group $G$ with its dual $\hat G$. The method is based upon the Pontryagin duality…

Quantum Physics · Physics 2022-09-20 Grigori Amosov

Quantum steering, a type of quantum correlation with unique asymmetry, has important applications in asymmetric quantum information tasks. We consider a new quantum steering scenario in which one half of a two-qubit Werner state is…

Quantum Physics · Physics 2021-10-12 Xinhong Han , Ya Xiao , Huichao Qu , Runhong He , Xuan Fan , Tian Qian , Yongjian Gu

We address the class of positive operator-valued measures (POVMs) for qubit systems that are obtained by coupling the signal qubit with a probe qubit and then performing a projective measurement on the sole probe system. These POVMs, which…

Quantum Physics · Physics 2015-10-27 Carlo Sparaciari , Matteo G. A. Paris
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