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Related papers: Towards a Faithful Quantumness Certification Funct…

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Fidelity is a fundamental measure for the closeness of two quantum states, which is important both from a theoretical and a practical point of view. Yet, in general, it is difficult to give good estimates of fidelity, especially when one…

Quantum Physics · Physics 2022-03-31 András Gilyén , Alexander Poremba

General quasi-probabilities are introduced to visualize time-dependent quantum correlations of light in phase space. They are based on the generalization of the Glauber-Sudarshan P function to a time-dependent P functional [W. Vogel, Phys.…

Quantum Physics · Physics 2017-06-14 Fabian Krumm , Werner Vogel , Jan Sperling

One of the many interesting features of quantum nonlocality is that the states of a multipartite quantum system cannot always be distinguished as well by local measurements as they can when all quantum measurements are allowed. In this…

Quantum Physics · Physics 2013-11-14 Somshubhro Bandyopadhyay , Michael Nathanson

We provide a scheme for efficient simulation of a broad class of quantum optics experiments. Our efficient simulation extends the continuous variable Gottesman-Knill theorem to a large class of non-Gaussian mixed states, thereby identifying…

Quantum Physics · Physics 2013-02-19 Victor Veitch , Nathan Wiebe , Christopher Ferrie , Joseph Emerson

We develop an enhanced technique for characterizing quantum optical processes based on probing unknown quantum processes only with coherent states. Our method substantially improves the original proposal [M. Lobino et al., Science 322, 563…

In this paper, using an exponential function of intensity of radiation field, two new classes of nonlinear coherent states will be constructed. For the first class, we choose the nonlinearity function as f(n) = exp(\beta n), where \beta…

Quantum Physics · Physics 2010-11-17 M. K. Tavassoly

Bosonic qubits are a promising route to building fault-tolerant quantum computers on a variety of physical platforms. Studying the performance of bosonic qubits under realistic gates and measurements is challenging with existing analytical…

We generalize the experimental success criterion for quantum teleportation/memory in continuous-variable quantum systems to be suitable for non-unit-gain condition by considering attenuation/amplification of the coherent-state amplitude.…

Quantum Physics · Physics 2008-09-29 Ryo Namiki , Masato Koashi , Nobuyuki Imoto

Efficiently characterizing large quantum states and processes is a central yet notoriously challenging task in quantum information science, as conventional tomography methods typically require resources that grow exponentially with system…

Quantum Physics · Physics 2026-03-03 Chenyang Li , Shengxin Zhuang , Yukun Zhang , Jingbo B. Wang , Xiao Yuan , Yusen Wu , Chuan Wang

Dissimilar notions of quantum correlations have been established, each being motivated through particular applications in quantum information science and each competing for being recognized as the most relevant measure of quantumness. In…

Quantum Physics · Physics 2021-05-05 S. Köhnke , E. Agudelo , M. Schünemann , O. Schlettwein , W. Vogel , J. Sperling , B. Hage

When applied to different input states, an imperfect quantum operation yields output states with varying fidelities, defined as the absolute square of their overlap with the desired states. We present an expression for the distribution of…

Quantum Physics · Physics 2009-02-26 Line Hjortshoj Pedersen , Niels Martin Moller , Klaus Molmer

According to a classical result due to Hudson, the Wigner function of a pure, continuous variable quantum state is non-negative if and only if the state is Gaussian. We have proven an analogous statement for finite-dimensional quantum…

Quantum Physics · Physics 2007-05-23 David Gross

In the Hilbert space of a quantum particle the standard coherent-state resolution of unity is written in terms of a phase-space integration of the outer product $|z\rangle \langle z|$. Because no pair of coherent states is orthogonal, one…

Quantum Physics · Physics 2016-03-28 Fernando Parisio

Universal quantum computing requires nonstabilizer (magic) quantum states. Quantifying the nonstabilizerness and relating it to other quantum resources is vital for characterizing the complexity of quantum many-body systems. In this work,…

Quantum Physics · Physics 2023-10-18 Xhek Turkeshi , Marco Schirò , Piotr Sierant

Coarse graining is a common imperfection of realistic quantum measurement, obstructing the direct observation of quantum features. Under highly coarse-grained measurement, we experimentally detect the continuous-variable nonclassicality of…

Quantum Physics · Physics 2023-10-19 Chan Roh , Young-Do Yoon , Jiyong Park , Young-Sik Ra

Quantum coherence is a fundamental aspect of quantum physics and plays a central role in quantum information science. This essential property of the quantum states could be fragile under the influence of the quantum operations. The extent…

Quantum Physics · Physics 2018-10-18 Fereshte Shahbeigi , Seyed Javad Akhtarshenas

While the standard formulation of quantum theory assumes a fixed background causal structure, one can relax this assumption within the so-called process matrix framework. Remarkably, some processes, termed causally nonseparable, are…

Quantum Physics · Physics 2022-08-29 Hippolyte Dourdent , Alastair A. Abbott , Nicolas Brunner , Ivan Šupić , Cyril Branciard

In this report we study certification of quantum measurements, which can be viewed as the extension of quantum hypotheses testing. This extension involves also the study of the input state and the measurement procedure. Here, we will be…

Non-Gaussian quantum states, described by negative valued Wigner functions, are important both for fundamental tests of quantum physics and for emerging quantum information technologies. However, they are vulnerable to dissipation. It is…

Quantum Physics · Physics 2022-01-11 B. Nugmanov , N. Zunikov , F. Ya. Khalili

We present Bell-type tests of nonclassicality and non-Gaussianity for single-mode fields employing a generalized quasiprobability function. Our nonclassicality tests are based on the observation that two orthogonal quadratures in phase…

Quantum Physics · Physics 2016-01-05 Jiyong Park , Hyunchul Nha
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