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We present a phase space description of the process of quantum teleportation for a system with an $N$ dimensional space of states. For this purpose we define a discrete Wigner function which is a minor variation of previously existing ones.…

Quantum Physics · Physics 2009-11-07 Juan Pablo Paz

We present an experimental realisation of the direct scheme for measuring the Wigner function of a single quantized light mode. In this method, the Wigner function is determined as the expectation value of the photon number parity operator…

Quantum Physics · Physics 2007-05-23 K. Banaszek , C. Radzewicz , K. Wodkiewicz , J. S. Krasinski

We show that Wigner-Leggett-Caldeira equation for Wigner phase space distribution function which describes the quantum Brownian motion of a particle in a force field in a high temerature, Ohmic environment can be identified as a…

Statistical Mechanics · Physics 2009-10-31 Jyotipratim Ray Chaudhuri , Bidhan Chandra Bag , Deb Shankar Ray

Phase-space features of the Wigner flow for an anharmonic quantum system driven by the harmonic oscillator potential modified by the addition of an inverse square (one-dimension Coulomb-like) contribution are analytically described in terms…

Quantum Physics · Physics 2018-12-05 Alex E. Bernardini

We analyze the tunneling of a particle through a repulsive potential resulting from an inverted harmonic oscillator in the quantum mechanical phase space described by the Wigner function. In particular, we solve the partial differential…

Quantum Physics · Physics 2013-06-07 D. M. Heim , W. P. Schleich , P. M. Alsing , J. P. Dahl , S. Varro

This work is an extended version of the paper arXiv:0803.2669v1[math-ph], in which the main results were announced. We consider certain classical diffusion process for a wave function on the phase space. It is shown that at the time of…

Mathematical Physics · Physics 2008-12-31 E. M. Beniaminov

Propagation of the Wigner function is studied on two levels of semiclassical propagation, one based on the van-Vleck propagator, the other on phase-space path integration. Leading quantum corrections to the classical Liouville propagator…

Quantum Physics · Physics 2007-05-23 Thomas Dittrich , Luis Sandoval , Carlos Viviescas

We introduce a family of criteria to detect quantum non-Gaussian states of a harmonic oscillator, that is, quantum states that can not be expressed as a convex mixture of Gaussian states. In particular we prove that, for convex mixtures of…

Newly introduced equilibrium Wigner functions for particles with spin one-half are used in the semi-classical kinetic equations to study a possible relation between thermal vorticity and spin polarization. It is shown that in global…

Nuclear Theory · Physics 2022-09-21 Avdhesh Kumar

We investigate particle production \`a la Schwinger mechanism in an expanding, flat de Sitter patch as is relevant for the inflationary epoch of our universe. Defining states and particle content in curved spacetime is certainly not a…

General Relativity and Quantum Cosmology · Physics 2017-09-11 Ramkishor Sharma , Suprit Singh

The Weyl-Wigner-Moyal formalism for quantum particle with discrete internal degrees of freedom is developed. A one to one correspondence between operators in the Hilbert space $L^{2}(\mathbb{R}^{3})\otimes{\mathcal{H}}^{(s+1)}$ and…

Quantum Physics · Physics 2020-02-19 Maciej Przanowski , Jaromir Tosiek , Francisco J. Turrubiates

We estimate the quantum state of a light beam from results of quantum homodyne measurements performed on identically prepared pulses. The state is represented through the Wigner function, a ``quasi-probability density'' on $\mathbb{R}^{2}$…

Statistics Theory · Mathematics 2011-06-23 Madalin Guta , Luis Artiles

A generalized Weyl quantization formalism for a particle on the circle investigated in \cite{1} is developed. A Wigner function for the state $\hat{\varrho}$ and the kernel $\mathcal{K}$ for a particle on the circle is defined and its…

Mathematical Physics · Physics 2015-06-18 Maciej Przanowski , Przemyslaw Brzykcy , Jaromir Tosiek

We proposed a distributed approximating functional method for efficiently describing the electronic dynamics in atoms and molecules in the presence of the Coulomb singularities, using the kernel of a grid representation derived by using the…

Computational Physics · Physics 2016-04-05 Zhigang Sun

The inexactness of the time-dependent Schr\"odinger equation of a charged particle in an external electromagnetic field is discussed in terms of the damping effect of the radiation. A possible improvement is to add a nonlinear term…

Quantum Physics · Physics 2011-06-07 Ji Luo

The time evolution of the Wigner function for Gaussian states generated by Lindblad quantum dynamics is investigated in the semiclassical limit. A new type of phase-space dynamics is obtained for the centre of a Gaussian Wigner function,…

Quantum Physics · Physics 2019-02-01 E M Graefe , B Longstaff , T Plastow , R Schubert

In the beginning of the 1950's, Wigner introduced a fundamental deformation from the canonical quantum mechanical harmonic oscillator, which is nowadays sometimes called a Wigner quantum oscillator or a parabose oscillator. Also, in quantum…

Mathematical Physics · Physics 2008-06-27 E. I. Jafarov , S. Lievens , J. Van der Jeugt

We calculate ground-state energies and densities of a helium atom confined in an impenetrable spherical box within density functional theory. These calculations are performed by variationally solving Kohn-Sham equation with the ground-state…

Atomic Physics · Physics 2010-06-24 Subhajit Waugh , Avijit Chowdhury , Arup Banerjee

We show how to represent the state and the evolution of a quantum computer (or any system with an $N$--dimensional Hilbert space) in phase space. For this purpose we use a discrete version of the Wigner function which, for arbitrary $N$, is…

Quantum Physics · Physics 2009-11-07 Pablo Bianucci , Cesar Miquel , Juan Pablo Paz , Marcos Saraceno

A semiclassical theory of dissipative Henon-Heiles system is proposed. Based on $\hbar$-scaling of an equation for evolution of Wigner quasiprobability distribution function in presence of dissipation and thermal diffusion, we derive a…

chao-dyn · Physics 2015-06-24 Bidhan Chandra Bag , Deb Shankar Ray