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We discuss a method of solving the time dependent Schrodinger equation for atoms with two active electrons in a strong laser field, which we used in a previous paper [A. Scrinzi and B. Piraux, Phys. Rev. A 56, R13 (1997)] to calculate…

Atomic Physics · Physics 2014-05-19 Armin Scrinzi , Bernard Piraux

A method to build various integrable models for description of coherent excitation of multilevel media by laser pulses is suggested. Distribution functions over the energy levels of quantum systems depending on the time and frequency…

Quantum Physics · Physics 2014-04-07 Vadim A. Savva , Vadim I. Zelenkov

We propose a novel and systematic recurrence method for the energy spectra of non-Hermitian systems under open boundary conditions based on the recurrence relations of their characteristic polynomials. Our formalism exhibits better accuracy…

Mesoscale and Nanoscale Physics · Physics 2025-04-16 Haoyan Chen , Yi Zhang

We present a two-timescale Floquet method that allows one to apply the Kramers-Henneberger approach to short pulses and arbitrary laser frequencies. An efficient numerical procedure to propagate the Floquet Hamiltonian is provided that…

Atomic Physics · Physics 2018-02-06 Lukas Medišauskas , Ulf Saalmann , Jan-Michael Rost

It has been demonstrated that Lattice Boltzmann schemes (LBSs) are very efficient for Computational AeroAcoustics (CAA). In order to handle the issue of absorbing acoustic boundary conditions for LBS, three kinds of damping terms are…

Computational Physics · Physics 2012-03-30 Hui Xu , Pierre Sagaut

A formulation of quantum electrodynamics is given that applies to atoms in a strong laser field by perturbation theory in a non-relativistic regime. Dipole approximation is assumed. The dual Dyson series, here discussed by referring it to…

Quantum Physics · Physics 2007-05-23 Marco Frasca

We investigate the dephasing dynamics of a qubit as an effective mechanism for estimating the temperature of its surrounding environment for different symmetrizes. Our approach is fundamentally quantum, leveraging the qubit's susceptibility…

Quantum Physics · Physics 2025-09-16 Anass Hminat , Abdallah Slaoui , Rachid Ahl Laamara , Mourad Telmini

We measure the coherent scattering of low-intensity, near-resonant light by a cloud of laser-cooled two-level rubidium atoms with a size comparable to the wavelength of light. We isolate a two-level atomic structure by applying a 300G…

We propose a simple method of combined synchronous modulations to generate the analytically exact solutions for a parity-time symmetric two-level system. Such exact solutions are expressible in terms of simple elementary functions and…

Quantum Physics · Physics 2017-06-07 Xiaobing Luo , Baiyuan Yang , Xiaofei Zhang , Lei Li , Xiaoguang Yu

We study quantum decoherence numerically in a system consisting of a relativistic quantum field theory coupled to a measuring device that is itself coupled to an environment. The measuring device and environment are treated as quantum,…

Quantum Physics · Physics 2020-10-13 Chris Nagele , Oliver Janssen , Matthew Kleban

We propose a relaxation time approximation for the description of the dynamics of strongly excited fermion systems. Our approach is based on time-dependent density functional theory at the level of the local density approximation. This…

Atomic and Molecular Clusters · Physics 2016-01-26 P. -G. Reinhard , E. Suraud

An approach, called discretized environment method, is introduced to treat exactly non-Markovian effects in open quantum systems. In this approach, a complex environment described by a spectral function is mapped into a finite set of…

Quantum Physics · Physics 2015-06-22 Denis Lacroix , V. V. Sargsyan , G. G. Adamian , N. V. Antonenko

We show that the von Neumann's algorithm of reduction (i.e. the algorithm of calculating the density matrix of the observable subsystem from the density matrix of the closed quantum system) corresponds to the special approximation at which…

Quantum Physics · Physics 2007-05-23 N. K. Solovarov

We study a first-order hyperbolic approximation of the nonlinear Schr\"odinger (NLS) equation. We show that the system is strictly hyperbolic and possesses a modified Hamiltonian structure, along with at least three conserved quantities…

We study the dynamics of relaxation and thermalization in an exactly solvable model of a particle interacting with a harmonic oscillator bath. Our goal is to understand the effects of non-Markovian processes on the relaxational dynamics and…

Condensed Matter · Physics 2009-10-31 S. M. Alamoudi , D. Boyanovsky , H. J. de Vega

We analyze how light-induced coherent population oscillations and ground-state Zeeman coherence in an atomic medium with degenerate two-level transitions can modify spectra of applied cw resonant radiation at the sub-mW power level. The use…

Atomic Physics · Physics 2015-05-28 A. M. Akulshin , R. J. McLean , A. I. Sidorov , P. Hannaford

The projection formalism for calculating effective Hamiltonians and resonances is generalized to the nonlocal and/or nonhermitian case, so that it is applicable to the reduction of relativistic systems (Bethe-Salpeter equations), and to…

High Energy Physics - Theory · Physics 2007-05-23 Arnold Neumaier

We discuss double ionization of atoms in strong laser pulses using a reduced dimensionality model. Following the insights obtained from an analysis of the classical mechanics of the process, we confine each electron to move along the lines…

Atomic Physics · Physics 2008-08-06 Jakub S. Prauzner-Bechcicki , Krzysztof Sacha , Bruno Eckhardt , Jakub Zakrzewski

The Navier-Stokes-Cahn-Hilliard (NSCH) system governs the diffuse-interface dynamics of two incompressible and immiscible fluids. We consider a relaxation approximation of the NSCH system that is composed by a system of first-order…

Numerical Analysis · Mathematics 2026-01-27 Jan Giesselmann , Jens Keim , Fabio Leotta , Christian Rohde

The interaction of a five-level atomic system involving electromagnetically induced transparency with four light fields is investigated. Two different light-atom configurations are considered, and their efficiency in generating large…

Optics · Physics 2009-11-11 Carlo Ottaviani , Stojan Rebic , David Vitali , Paolo Tombesi