English
Related papers

Related papers: Negativity of the Wigner function as an indicator …

200 papers

The presence of unique quantum correlations is the core of quantum information processing and general quantum theory. We address the fundamental question of how quantum correlations of a generic quantum system can be probed using…

Quantum Physics · Physics 2011-06-01 Adam Bednorz , Wolfgang Belzig

Conventional Glauber coherent states (CS) can be defined in several equivalent ways, e.g., by displacing the vacuum or, explicitly, by their infinite Poissonian expansion in Fock states. It is well known that these definitions become…

Quantum Physics · Physics 2022-06-10 Adam Miranowicz , Malgorzata Paprzycka , Anirban Pathak , Franco Nori

A measurement-induced continuous-variable logical gate is able to prepare Schr\"odinger cat states if the gate uses a non-Gaussian resource state, such as cubic phase state [I. V. Sokolov, Phys. Lett. A 384, 126762 (2020)]. Our scheme…

Quantum Physics · Physics 2021-12-08 N. I. Masalaeva , I. V. Sokolov

We propose an experiment demonstrating the nonlocality of a quantum singlet-like state generated from a single photon incident on a beam splitter. Each of the two spatially separated apparatuses in the setup performs a strongly unbalanced…

Quantum Physics · Physics 2009-10-31 Konrad Banaszek , Krzysztof Wodkiewicz

In this paper we study quantum dynamics of the bouncing cosmological model. We focus on the model of the flat Friedman-Robertson-Walker universe with a free scalar field. The bouncing behavior, which replaces classical singularity, appears…

General Relativity and Quantum Cosmology · Physics 2013-06-12 Jean Pierre Gazeau , Jakub Mielczarek , Wlodzimierz Piechocki

Within the framework of the probability representation of quantum mechanics, we study a superposition of generic Gaussian states associated to symmetries of a regular polygon of n sides; in other words, the cyclic groups (containing the…

Quantum Physics · Physics 2022-03-16 Julio A. López-Saldívar , Vladimir I. Man'ko , Margarita A. Man'ko

We examine the quantum states produced through parametric amplification with internal quantum noise. The internal diffusion arises by coupling both modes of light to a reservoir for the duration of the interaction time. The Wigner function…

Quantum Physics · Physics 2009-11-10 Sonja Daffer , Krzysztof Wodkiewicz , John K. McIver

We study Wigner function value statistics of classically chaotic quantum maps on compact 2D phase space. We show that the Wigner function statistics of a random state is a Gaussian, with the mean value becoming negligible compared to the…

Quantum Physics · Physics 2007-05-23 Martin Horvat , Tomaz Prosen

We examine the visualization of quantum mechanics in phase space by means of the Wigner function and the Wigner function flow as a complementary approach to illustrating quantum mechanics in configuration space by wave functions. The Wigner…

Quantum Physics · Physics 2011-01-17 Heiko Bauke , Noya Ruth Itzhak

We develop a resource theory for continuous-variable systems grounded on operations routinely available within current quantum technologies. In particular, the set of free operations is convex and includes quadratic transformations and…

Quantum Physics · Physics 2018-12-05 Francesco Albarelli , Marco G. Genoni , Matteo G. A. Paris , Alessandro Ferraro

A fluid analog of the information flux in the phase-space associated to purity and von Neumann entropy are identified in the Weyl-Wigner formalism of quantum mechanics. Once constrained by symmetry and positiveness, the encountered…

Quantum Physics · Physics 2018-01-17 Alex E. Bernardini , Orfeu Bertolami

In nonrelativistic quantum mechanics, Hudsons theorem states that a Gaussian wavefunction is the only pure state corresponding to a positive Wigner function (WF). We explicitly construct non Gaussian Dirac spinors with positive relativistic…

Quantum Physics · Physics 2014-10-13 Andre G. Campos , Renan Cabrera , Denys I. Bondar , Herschel Rabitz

We derive an analytical expression of a Wigner function that approximately describes the time evolution of the one-dimensional motion of a particle in a nonharmonic potential. Our method involves two exact frame transformations, accounting…

Measuring the quantumness of a system can be done with a variety of methods. In this article we compare different criteria, namely quantum discord, Bell inequality violation and non-separability, for systems placed in a Gaussian state. When…

Quantum Physics · Physics 2023-04-19 Jerome Martin , Amaury Micheli , Vincent Vennin

Viewed as approximations to quantum mechanics, classical evolutions can violate the positive-semidefiniteness of the density matrix. The nature of this violation suggests a classification of dynamical systems based on classical-quantum…

Quantum Physics · Physics 2009-11-06 Salman Habib , Kurt Jacobs , Hideo Mabuchi , Robert Ryne , Kosuke Shizume , Bala Sundaram

We show that real polarization method can be effectively used to geometrically quantize physical systems with compact phase space, like the spin. Our method enables us to construct a wave function of a qubit in both position and momentum…

Mathematical Physics · Physics 2015-12-10 Jerzy Kijowski , Piotr Waluk , Katarzyna Senger

The question of witnessing or quantifying nonclassicality of quantum systems has been addressed in various ways. For a given system or theory, we propose identifying it with the incompatibility of admissible states. We quantify the…

Quantum Physics · Physics 2013-12-05 Pavan Iyengar , G. N. Chandan , R. Srikanth

In [Phys. Rev. A 70, 062101 (2004)] Gibbons et al. defined a class of discrete Wigner functions W to represent quantum states in a finite Hilbert space dimension d. I characterize a set C_d of states having non-negative W simultaneously in…

Quantum Physics · Physics 2007-05-23 Ernesto F. Galvao

We show that quantum circuits where the initial state and all the following quantum operations can be represented by positive Wigner functions can be classically efficiently simulated. This is true both for continuous-variable as well as…

Quantum Physics · Physics 2015-06-11 A. Mari , J. Eisert

A Fokker-Planck equation for the Wigner function evolution in a noisy Kerr medium ($\chi^{(3)}$ non-linearity) is presented. We numerically solved this equation taking a coherent state as an initial condition. The dissipation effects are…

Quantum Physics · Physics 2010-05-04 Magdalena Stobińska , G. J. Milburn , Krzysztof Wódkiewicz