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Related papers: Time-dependent complete-active-space self-consiste…

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We investigate a two-level atom in the field of a strong laser pulse. The resulting time-dependent polarization is the source of a radiation the frequency components of which are essentially harmonics of the driving field's carrier…

Quantum Physics · Physics 2016-09-13 Ákos Gombkötő , Attila Czirják , Sándor Varró , Péter Földi

We present a linear scaling formulation for the solution of the all-electron Coulomb problem in crystalline solids. The resulting method is systematically improvable and well suited to large-scale quantum mechanical calculations in which…

Materials Science · Physics 2021-11-09 J. E. Pask , N. Sukumar , S. E. Mousavi

We explore the computation of high-harmonic generation spectra by means of Gaussian basis sets in approaches propagating the time-dependent Schr{\"o}dinger equation. We investigate the efficiency of Gaussian functions specifically designed…

We propose a novel adaptive damping algorithm for the self-consistent field (SCF) iterations of Kohn-Sham density-functional theory, using a backtracking line search to automatically adjust the damping in each SCF step. This line search is…

Materials Science · Physics 2022-03-14 Michael F. Herbst , Antoine Levitt

We investigate the generation of higher-order harmonics from a quantum optics perspective via the interaction of a semiconductor with a coherent pump field focusing on the regime where strong-field intraband excitations dominate. The…

We present theoretical studies of high-order harmonic generation (HHG) produced by non-homogeneous fields as resulting from the illumination of plasmonic nanostructures with a short laser pulse. We show that both the inhomogeneity of the…

Atomic Physics · Physics 2012-04-27 M. F. Ciappina , J. Biegert , R. Quidant , M. Lewenstein

We report calculations of the high harmonic generation spectra of the C\textsubscript{60} fullerene molecule, employing a diverse set of real-time time-dependent quantum chemical methods. All methodologies involve expanding the propagated…

Chemical Physics · Physics 2023-12-05 Aleksander P. Woźniak , Robert Moszyński

We study photoelectron angular distributions (PADs) near the ionization threshold with a newly developed Coulomb quantum-orbit strong-field approximation (CQSFA) theory. The CQSFA simulations present an excellent agreement with the result…

Alignment and orientation of molecules by intense, ultrashort laser fields are crucial for a variety of applications in physics and chemistry. These include control of high harmonics generation, molecular orbitals tomography, control of…

We investigate the high harmonic generation (HHG) from solids by simulating the dynamics of a single active electron in periodic potentials. The corresponding time-dependent Schr\"odinger equations (TDSE) are solved numerically by using…

Atomic Physics · Physics 2016-03-31 Zhong Guan , Xiao-Xin Zhou , Xue-Bin Bian

We show how to perform accurate, nonperturbative and controlled calculations in quantum field theory in d dimensions. We use the Truncated Conformal Space Approach (TCSA), a Hamiltonian method which exploits the conformal structure of the…

High Energy Physics - Theory · Physics 2015-12-04 Matthijs Hogervorst , Slava Rychkov , Balt C. van Rees

Harmonic generation is a general characteristic of driven nonlinear systems, and serves as an efficient tool for investigating the fundamental principles that govern the ultrafast nonlinear dynamics. In atomic gases, high-harmonic radiation…

High-order harmonic generation (HHG) from aligned acetylene molecules interacting with mid infra-red (IR), linearly polarized laser pulses is studied theoretically using a mixed quantum-classical approach in which the electrons are…

Atomic Physics · Physics 2018-05-18 Peter Mulholland , Daniel Dundas

We theoretically propose a multidimensional high-harmonic echo spectroscopy technique which utilizes strong optical fields to resolve coherent electron dynamics spanning an energy range of multiple electron Volts. Using our recently…

We use three dimensional time-dependent Schr\"odinger equation (3D--TDSE) to calculate angular electron momentum distributions and photoelectron spectra of atoms driven by spatially inhomogeneous fields. An example for such inhomogeneous…

Atomic Physics · Physics 2013-06-26 M. F. Ciappina , J. A. Pérez-Hernández , T. Shaaran , L. Roso , M. Lewenstein

The terahertz (THz) generation in a dual-color field was investigated experimentally by precisely controlling the relative time delay $\tau$ and polarization $\theta$ of dual-color lasers, where the accompanying third-harmonic generation…

Optics · Physics 2020-12-07 Kaixuan Zhang , Yizhu Zhang , T. -M. Yan , Y. H. Jiang

We introduce a new implementation of time-dependent density-functional theory which allows the \emph{entire} spectrum of a molecule or extended system to be computed with a numerical effort comparable to that of a \emph{single} standard…

Materials Science · Physics 2009-11-13 Dario Rocca , Ralph Gebauer , Yousef Saad , Stefano Baroni

In this work, we develop a new orbital optimization approach, perturbative Super-CI (Super-CIPT), for the two-component complete active space self-consistent field (2C-CASSCF) method. By variationally optimizing spinor orbitals and…

Chemical Physics · Physics 2026-03-04 Yang Guo , Achintya Kumar Dutta

We generalize and test the recent "ab initio" self-consistent (AISC) time-independent semiclassical laser theory. This self-consistent formalism generates all the stationary lasing properties in the multimode regime (frequencies,…

Optics · Physics 2008-10-12 Li Ge , Robert J. Tandy , A. Douglas Stone , Hakan E. Türeci

High-harmonic generation (HHG) is a highly nonlinear optical process that typically requires an intense laser to trigger emissions at integer multiples of the driving field frequency. However, the strong fields required for conventional HHG…

Optics · Physics 2025-12-05 Lu Wang , Andrew M. Parks , Adam Thorpe , Graeme Bart , Giulio Vampa , Thomas Brabec