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We study the tunnelling trough a potential barrier of the system of two quantum correlated particles. The system is considered in one dimension. The interaction with the barrier and between particles is approximated by $\delta$-potentials.…

Mathematical Physics · Physics 2016-09-07 S. A. Avdonin , L. A. Dmitrieva , Yu. A. Kuperin , G. E. Rudin

We analyze the self-averaging properties of time-reversed solutions of the paraxial wave equation with random coefficients, which we take to be Markovian in the direction of propagation. This allows us to construct an approximate martingale…

Chaotic Dynamics · Physics 2007-05-23 Guillaume Bal , George Papanicolaou , Leonid Ryzhik

The Wigner function W(q,p) is formulated as a phase-space path integral, whereby its sign oscillations can be seen to follow from interference between the geometrical phases of the paths. The approach has similarities to the path-centroid…

Quantum Physics · Physics 2009-11-10 J. H. Samson

The two-dimensional hydrogen atom in an external magnetic field is considered in the context of phase space. Using solution of the Schr\"{o}dinger equation in phase space the Wigner function related to the Zeeman effect is calculated. For…

Quantum Physics · Physics 2019-11-27 R. A. S. Paiva , R. G. G. Amorim , S. C. Ulhoa , A. E. Santana , F. C. Khanna

We introduce the Wigner functional representing a quantum field in terms of the field amplitudes and their conjugate momenta. The equation of motion for the functional of a scalar field point out the relevance of solutions of the classical…

High Energy Physics - Theory · Physics 2010-11-01 S. Mrowczynski , B. Mueller

For a quantum harmonic oscillator an explicit expression that describes the energy distribution as a coordinate function is obtained. The presence of the energy function poles is shown for the quantum system in domains where the Wigner…

Quantum Physics · Physics 2021-05-11 E. E. Perepelkin , B. I. Sadovnikov , N. G. Inozemtseva , E. V. Burlakov

The phase-space path-integral approach to the damped harmonic oscillator is analyzed beyond the Markovian approximation. It is found that pairs of nonclassical trajectories contribute to the path-integral representation of the Wigner…

Quantum Physics · Physics 2010-10-07 Leonardo A. Pachon , Gert-Ludwig Ingold , Thomas Dittrich

The tomographic invertable map of the Wigner function onto the positive probability distribution function is studied. Alternatives to the Schr\"odinger evolution equation and to the energy level equation written for the positive probability…

Quantum Physics · Physics 2016-09-08 Vladimir I. Man'ko

We study the quantum tunnelling of a very complex object of which only part is coupled to an external potential ( the potential barrier ). We treat this problem as the tunnelling of a particle (part of the system affected by the potential)…

Condensed Matter · Physics 2008-02-03 A. H. Castro Neto , A. O. Caldeira

Classical surfaces in phase space correspond to quantum states in Hilbert space. Subsystems specify factor spaces of the Hilbert space. An entangled state corresponds semiclassically to a surface that cannot be decomposed into a product of…

Quantum Physics · Physics 2007-05-23 A. M. Ozorio de Almeida

The quantum phase-space dynamics driven by hyperbolic P\"oschl-Teller (PT) potentials is investigated in the context of the Weyl-Wigner quantum mechanics. The obtained Wigner functions for quantum superpositions of ground and first-excited…

Quantum Physics · Physics 2019-09-24 Alex E. Bernardini , Roldao Da Rocha

We represent both the states and the evolution of a quantum computer in phase space using the discrete Wigner function. We study properties of the phase space representation of quantum algorithms: apart from analyzing important examples,…

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

We study time evolution of Wigner function of an initially interacting one-dimensional quantum gas following the switch-off of the interactions. For the scenario where at $t=0$ the interactions are suddenly suppressed, we derive a…

Quantum Gases · Physics 2020-07-15 Kamel Bencheikh , Luis M. Nieto

In quantum cosmological models, constructed in the framework of Friedmann-Robertson-Walker metrics, a nucleation of the Universe with its further expansion is described as a tunneling transition through an effective barrier between regions…

General Relativity and Quantum Cosmology · Physics 2008-12-18 Sergei P. Maydanyuk

We investigate quantum properties of pulsed light fields point by point in phase space. We probe the negative region of the Wigner function of a single photon generated by the means of waveguided parametric down-conversion. This capability…

Quantum Physics · Physics 2010-12-24 Kaisa Laiho , Katiuscia N. Cassemiro , David Gross , Christine Silberhorn

There remains the old question of how long a quantum particle takes to tunnel through a potential barrier higher than its incident kinetic energy. In this article a solution of the question is proposed on the basis of a realistic…

Quantum Physics · Physics 2007-06-26 Wang Guowen

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

We construct, using simple geometrical arguments, a Wigner function defined on a discrete phase space of arbitrary integer Hilbert-space dimension that is free of redundancies. ``Ghost images'' plaguing other Wigner functions for discrete…

Quantum Physics · Physics 2009-11-11 Arturo Argüelles , Thomas Dittrich

Representations of quantum state vectors by complex phase space amplitudes, complementing the description of the density operator by the Wigner function, have been defined by applying the Weyl-Wigner transform to dyadic operators, linear in…

Quantum Physics · Physics 2015-05-19 A. J. Bracken , P. Watson

We consider the time-independent Wigner functions of phase-space quantum mechanics (a.k.a. deformation quantization) for a Morse potential. First, we find them by solving the $\ast$-eigenvalue equations, using a method that can be applied…

Mathematical Physics · Physics 2010-02-03 B. Belchev , M. A. Walton