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Related papers: Semiclassical theory for small displacements

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The semiclassical Wigner function for a Bohr-quantized energy eigenstate is known to have a caustic along the corresponding classical closed phase space curve in the case of a single degree of freedom. Its Fourier transform, the…

Quantum Physics · Physics 2010-03-10 Eduardo Zambrano , Alfredo M Ozorio de Almeida

The strictly classical propagation of an initial Wigner function, referred to as TWA or LSC-IVR, is considered to provide approximate averages, despite not being a true Wigner function: it does not represent a positive operator. We here…

Quantum Physics · Physics 2024-06-28 Kelvin Titimbo , Gabriel M. Lando , Alfredo M. Ozorio de Almeida

The intensity of the overlap of a quantum state with all its phase space translations defines its quantum correlations. In the case of pure states, these are invariant with respect to Fourier transformation. The overlaps themselves are here…

Quantum Physics · Physics 2009-11-10 Alfredo M. Ozorio de Almeida , Raul O. Vallejos , Marcos Saraceno

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

Transition from quantum to semiclassical behaviour and loss of quantum coherence for inhomogeneous perturbations generated from a non-vacuum initial state in the early Universe is considered in the Heisenberg and the Schr\"odinger…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Julien Lesgourgues , David Polarski , Alexei A. Starobinsky

We develop a semi-classical approximation for the scar function in the Weyl-Wigner representation in the neighborhood of a classically unstable periodic orbit of chaotic two dimensional systems. The prediction of hyperbolic fringes,…

Quantum Physics · Physics 2009-11-13 Alejandro M. F. Rivas

The work distribution is a fundamental quantity in nonequilibrium thermodynamics mainly due to its connection with fluctuations theorems. Here we develop a semiclassical approximation to the work distribution for a quench process in chaotic…

Quantum Physics · Physics 2017-05-17 Ignacio García-Mata , Augusto J. Roncaglia , Diego A. Wisniacki

The Weyl-Wigner representation of quantum mechanics allows one to map the density operator in a function in phase space - the Wigner function - which acts like a probability distribution. In the context of statistical mechanics, this…

Quantum Physics · Physics 2023-08-31 Marcos Gil de Oliveira , Alfredo Miguel Ozorio de Almeida

In this work we study the Wigner functions, which are the quantum analogues of the classical phase space density, and show how a full rigorous semiclassical scheme for all orders of \hbar can be constructed for them without referring to the…

Chaotic Dynamics · Physics 2009-11-07 Gregor Veble , Marko Robnik , Valery Romanovski

The Quantum Ergodic Conjecture equates the Wigner function for a typical eigenstate of a classically chaotic Hamiltonian with a delta-function on the energy shell. This ensures the evaluation of classical ergodic expectations of simple…

Quantum Physics · Physics 2015-05-20 E. Zambrano , W. P. Karel Zapfe , Alfredo M. Ozorio de Almeida

In this paper, we correct a mistake we made in [Phys. Rev. Lett. $\textbf{122}$, 190402 (2019)] and [Phys. Rev. A $\textbf{103}$, 012213 (2021)] regarding the Wigner function of the so-called smoothed Weak-Valued state (SWV state). Here…

Quantum Physics · Physics 2025-08-07 Kiarn T. Laverick , Areeya Chantasri , Howard M. Wiseman

Shor's algorithms for factorization and discrete logarithms on a quantum computer employ Fourier transforms preceding a final measurement. It is shown that such a Fourier transform can be carried out in a semi-classical way in which a…

Quantum Physics · Physics 2009-10-28 Robert B. Griffiths , Chi-Sheng Niu

We investigate transport properties of quantized chaotic systems in the short wavelength limit. We focus on non-coherent quantities such as the Drude conductance, its sample-to-sample fluctuations, shot-noise and the transmission spectrum,…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Ph. Jacquod , Robert S. Whitney

A function of positive type can be defined as a positive functional on a convolution algebra of a locally compact group. In the case where the group is abelian, by Bochner's theorem a function of positive type is, up to normalization, the…

Mathematical Physics · Physics 2014-11-06 Paolo Aniello

We elucidate the basic physical mechanisms responsible for the quantum-classical transition in one-dimensional, bounded chaotic systems subject to unconditioned environmental interactions. We show that such a transition occurs due to the…

Quantum Physics · Physics 2007-10-18 Benjamin D. Greenbaum , Salman Habib , Kosuke Shizume , Bala Sundaram

The Wigner function is a quantum analogue of the classical joined distribution of position and momentum. As such is should be a good tool to study quantum-classical correspondence. In this paper, the classical limit of the Wigner function…

Quantum Physics · Physics 2021-04-15 Jan Mostowski , Joanna Pietraszewicz

An initial coherent state is propagated exactly by a kicked quantum Hamiltonian and its associated classical stroboscopic map. The classical trajectories within the initial state are regular for low kicking strengths, then bifurcate and…

Chaotic Dynamics · Physics 2019-07-16 Gabriel M. Lando , Alfredo M. Ozorio de Almeida

We present a comprehensive study of semiclassical phase-space propagation in the Wigner representation, emphasizing numerical applications, in particular as an initial-value representation. Two semiclassical approximation schemes are…

Chemical Physics · Physics 2010-07-01 Thomas Dittrich , Edgar A. Gomez , Leonardo A. Pachon

The Heisenberg evolution of a given unitary operator corresponds classically to a fixed canonical transformation that is viewed through a moving coordinate system. The operators that form the bases of the Weyl representation and its Fourier…

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

We show that the quantum wavefunction, interpreted as the probability density of finding a single non-localized quantum particle, which evolves according to classical laws of motion, is an intermediate description of a material quantum…

Quantum Physics · Physics 2007-05-23 Daniela Dragoman
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