English
Related papers

Related papers: Magnus-Lanczos methods with simplified commutators…

200 papers

Grid-based discretizations of the time dependent Schr\"odinger equation coupled to an external magnetic field are converted to manifest gauge invariant discretizations. This is done using generalizations of ideas used in classical lattice…

Computational Physics · Physics 2015-05-13 Tore Gunnar Halvorsen , Simen Kvaal

The integrating factor technique is widely used to solve numerically (in particular) the Schr\"odinger equation in the context of spectral methods. Here, we present an improvement of this method exploiting the freedom provided by the gauge…

Analysis of PDEs · Mathematics 2023-02-14 Martino Lovisetto , D Clamond , B Marcos

In this paper a class of oscillatory integrals is interpreted as a limit of Lebesgue integrals with Gaussian regularizers. The convergence of the regularized integrals is shown with an improved version of iterative integration by parts that…

Functional Analysis · Mathematics 2024-07-16 Jussi Behrndt , Peter Schlosser

Linear combinations of complex gaussian functions, where the linear and nonlinear parameters are allowed to vary, are shown to provide an extremely flexible and effective approach for solving the time-dependent Schr\"odinger equation in one…

Quantum Physics · Physics 2023-03-08 Simen Kvaal , Caroline Lasser , Thomas Bondo Pedersen , Ludwik Adamowicz

Two families of symplectic methods specially designed for second-order time-dependent linear systems are presented. Both are obtained from the Magnus expansion of the corresponding first-order equation, but otherwise they differ in…

Numerical Analysis · Mathematics 2024-04-22 Philipp Bader , Sergio Blanes , Fernando Casas , Nikita Kopylov , Enrique Ponsoda

Recent work found that an analysis formalism based on the Lanczos algorithm allows energy levels to be extracted from Euclidean correlation functions with faster ground-state convergence than effective masses, convergent estimators for…

High Energy Physics - Lattice · Physics 2025-09-12 Daniel C. Hackett , Michael L. Wagman

Quantum Monte Carlo methods are first-principle approaches that approximately solve the Schr\"odinger equation stochastically. As compared to traditional quantum chemistry methods, they offer important advantages such as the ability to…

Chemical Physics · Physics 2020-02-11 Jonas Feldt , Claudia Filippi

The Magnus expansion has long been a celebrated subject in numerical analysis, leading to the development of many useful classical integrators. More recently, it has been discovered to be a powerful tool for designing quantum algorithms for…

Numerical Analysis · Mathematics 2025-09-30 Di Fang , Jiaqi Zhang

Resonances which result from perturbation of embedded eigenvalues are studied by time dependent methods. A general theory is developed, with new and weaker conditions, allowing for perturbations of threshold eigenvalues and relaxed Fermi…

Mathematical Physics · Physics 2009-10-31 O. Costin , A. Soffer

We show that a pseudospectral representation of the wavefunction using multiple spatial domains of variable size yields a highly accurate, yet efficient method to solve the time-dependent Schr\"odinger equation. The overall spatial domain…

Quantum Physics · Physics 2016-12-06 R. Esteban Goetz , Andrea Simoni , Christiane P. Koch

The purpose of this document is to describe the solution and implementation of the time-independent and time-dependent Schr\"odinger using pseudospectral methods. Currently, the description is for single particle systems interacting with a…

Quantum Physics · Physics 2024-04-08 Håkon Kristiansen , Einar Aurbakken

Based on the generation function of Laguerre polynomials, We proposed a new Laguerre polynomial expansion scheme in the calculation of evolution of time dependent Schr\"odinger equation. Theoretical analysis and numerical test show that the…

Quantum Physics · Physics 2015-06-26 Jun Jing , H. R. Ma

We review and further develop the recently introduced numerical approach for scattering calculations based on a so called pseudo-time Schroedinger equation, which is in turn a modification of the damped Chebyshev polynomial expansion…

Chemical Physics · Physics 2007-05-23 V. A. Mandelshtam , A. Neumaier

Monte Carlo studies involving real time dynamics are severely restricted by the sign problem that emerges from highly oscillatory phase of the path integral. In this letter, we present a new method to compute real time quantities on the…

High Energy Physics - Lattice · Physics 2016-08-24 Andrei Alexandru , Gokce Basar , Paulo F. Bedaque , Sohan Vartak , Neill C. Warrington

The purpose of the present work is to expand substantially the type of control and estimation problems that can be addressed following the paradigm of Schr\"odinger bridges, by incorporating termination (killing) of stochastic flows.…

Optimization and Control · Mathematics 2024-06-24 Asmaa Eldesoukey , Olga Movilla Miangolarra , Tryphon T. Georgiou

Time dependent Schr\"odinger equations with conservative force field U commonly constitute a major challenge in the numerical approximation, especially when they are analysed in the semiclassical regime. Extremely high oscillations…

Numerical Analysis · Mathematics 2020-02-18 Winfried Auzinger , Harald Hofstätter , Othmar Koch , Karolina Kropielnicka , Pranav Singh

The Schr\"odinger-like equation written in terms of the displacement operator is solved analytically for a inverse square plus Coulomb-like potential. Starting from the new Hamiltonian, the effects of the spatially dependent mass on the…

Quantum Physics · Physics 2015-09-30 Altug Arda , Ramazan Sever

We show that, by using the quantum orthogonal functions invariant, we are able to solve a coupled of time dependent harmonic oscillators where all the time dependent frequencies are arbitrary. We do so, by transforming the time dependent…

We present the development of a LabVIEW multimedia module for introductory Quantum Physics courses and our experience in the use of this application as an educational tool in learning methodologies. The program solves the Time Dependent…

The explicit semiclassical treatment of logarithmic perturbation theory for the bound-state problem within the framework of the radial Klein-Gordon equation with attractive real-analytic screened Coulomb potentials, contained time-component…

Quantum Physics · Physics 2007-05-23 I. V. Dobrovolska , R. S. Tutik