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The semiclassically scaled time-dependent multi-particle Schr\"odinger equation describes, inter alia, quantum dynamics of nuclei in a molecule. It poses the combined computational challenges of high oscillations and high dimensions. This…

Numerical Analysis · Mathematics 2020-12-02 Caroline Lasser , Christian Lubich

Quantum states can be described equivalently by density matrices, Wigner functions or quantum tomograms. We analyze the accuracy and performance of three related semiclassical approaches to quantum dynamics, in particular with respect to…

Quantum Physics · Physics 2009-08-27 G. Schubert , V. S. Filinov , K. Matyash , R. Schneider , H. Fehske

We numerically compare the semiclassical ``frozen Gaussian'' Herman-Kluk propagator [Chem. Phys. 91, 27 (1984)] and the ``thawed Gaussian'' propagator put forward recently by Baranger et al. [J. Phys. A 34, 7227 (2001)] by studying the…

Quantum Physics · Physics 2009-11-10 C. Harabati , J. M. Rost , F. Grossmann

The semiclassical propagator in the representation of SU(n) coherent states is characterized by isolated classical trajectories subjected to boundary conditions in a doubled phase space. In this paper we recast this expression in terms of…

Quantum Physics · Physics 2011-07-05 Thiago F. Viscondi , Marcus A. M. de Aguiar

We analyze strong field atomic dynamics semiclassically, based on a full time-dependent description with the Hermann-Kluk propagator. From the properties of the exact classical trajectories, in particular the accumulation of action in time,…

Atomic Physics · Physics 2009-11-06 Gerd van de Sand , Jan M Rost

Phase-space representations based on coherent states (P, Q, Wigner) have been successful in the creation of stochastic differential equations (SDEs) for the efficient stochastic simulation of high dimensional quantum systems. However many…

Quantum Physics · Physics 2015-05-14 M. R. Hush , A. R. R. Carvalho , J. J. Hope

Time dependence for barrier penetration is considered in the phase space. An asymptotic phase-space propagator for nonrelativistic scattering on a one - dimensional barrier is constructed. The propagator has a form universal for various…

Quantum Physics · Physics 2009-10-30 M. S. Marinov , Bilha Segev

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 consider the singular semiclassical initial value problem for the phase space Schrodinger equation. We approximate semiclassical quantum evolution in phase space by analyzing initial states as superpositions of Gaussian wave packets and…

Mathematical Physics · Physics 2014-02-28 P. D. Karageorge , G. N. Makrakis

We present both full quantum mechanical and semiclassical calculations of above threshold ionization (ATI) of a hydrogen atom in the tunneling regime by a few-cycle linearly polarized infrared laser pulse. As a quantum treatment, we applied…

Atomic Physics · Physics 2017-04-26 Viktor Ayadi , Peter Foldi , Peter Dombi , Karoly Tokesi

We investigate the phase-space dynamics of the Kramers Henneberger (KH) atom solving the time-dependent Schr\"odinger equation for reduced-dimensionality models and using Wigner quasiprobability distributions. We find that, for the…

Quantum Physics · Physics 2025-03-27 A. Tasnim Aynul , L. Cruz Rodriguez , C. Figueira de Morisson Faria

The semiclassical formula for the coherent-state propagator is written in terms of complex classical trajectories of an equivalent classical system. Depending on the parameters involved, more than one trajectory may contribute to the…

Quantum Physics · Physics 2015-05-19 A. D. Ribeiro

Solving the time-dependent Schr\"odinger equation (TDSE) is pivotal for modeling non-adiabatic electron dynamics, a key process in ultrafast spectroscopy and laser-matter interactions. However, exact solutions to the TDSE remain…

Chemical Physics · Physics 2025-12-29 Bizi Huang , Weizhong Fu , Ji Chen

For a circularly polarized single-color field at a central frequency of $2\omega$ the final electron momentum distribution upon strong field ionization does not carry any information about the phase of the initial momentum distribution.…

Quantum Physics · Physics 2020-08-17 Sebastian Eckart

We analyze the semiclassical evolution of Gaussian wavepackets in chaotic systems. We prove that after some short time a Gaussian wavepacket becomes a primitive WKB state. From then on, the state can be propagated using the standard TDWKB…

Chaotic Dynamics · Physics 2009-11-13 Raphael N. P. Maia , Fernando Nicacio , Raul O. Vallejos , Fabricio Toscano

By using the overcompleteness of coherent states we find an alternative form of the unit operator for which the ket and the bra appearing under the integration sign do not refer to the same phase-space point. This defines a new quantum…

Quantum Physics · Physics 2015-03-13 Fernando Parisio

A trajectory segment in an energy shell, which combines to form a closed curve with a segment in another canonically driven energy shell, adds an oscillatory semiclassical contribution to the smooth classical background of the quantum…

Chaotic Dynamics · Physics 2022-10-12 Alfredo M. Ozorio de Almeida

The \emph{semiclassical Wigner treatment} of Brown and Heller [J. Chem. Phys. 75, 186 (1981)] is applied to triatomic direct photodissociations with the aim of accurately predicting final state distributions at relatively low computational…

Chemical Physics · Physics 2017-09-13 W. Arbelo-González , L. Bonnet , A. García-Vela

Complex-valued semiclassical methods hold out the promise of treating classically allowed and classically forbidden processes on the same footing. In addition, they provide a natural way to describe optical excitation with complex fields…

Quantum Physics · Physics 2017-08-23 Werner Koch , David J. Tannor

When the semiclassical Herman-Kluk propagator is used for evaluating quantum-mechanical observables or time-correlation functions, the initial conditions for the guiding trajectories are typically sampled from the Husimi density. Here, we…

Quantum Physics · Physics 2024-04-10 Fabian Kröninger , Caroline Lasser , Jiří Vaníček