arXiv subjects

Ali Abedi

Publications and source records attributed to Ali Abedi.

57 records · Page 4Linked to original sources

arXiv2013

Steps in the exact time-dependent potential energy surface

We study the exact Time-Dependent Potential Energy Surface (TDPES) in the presence of strong non-adiabatic coupling between the electronic and nuclear motion. The concept of the TDPES emerges from the exact factorization of the full electron-nuclear wave-function [A. Abedi, N. T. Maitra, and E. K. U. Gross, Phys. Rev. Lett. \textbf{105}, 123002 (2010)]. Employing a 1D model-system, we show that the TDPES exhibits a dynamical step that bridges between piecewise adiabatic shapes. We analytically investigate the position of the steps and the nature of the switching between the adiabatic pieces of the TDPES.

physics.chem-ph↗

arXiv2012

Correlated electron-nuclear dynamics: Exact factorization of the molecular wavefunction

It was recently shown [Phys. Rev. Lett. 105, 123002 (2010)] that the complete wavefunction for a system of electrons and nuclei evolving in a time-dependent external potential can be exactly factorized into an electronic wavefunction and a nuclear wavefunction. The concepts of an exact time-dependent potential energy surface (TDPES) and exact time-dependent vector potential emerge naturally from the formalism. Here we present a detailed description of the formalism, including a full derivation of the equations that the electronic and nuclear wavefunctions satisfy. We demonstrate the relationship of this exact factorization to the traditional Born-Oppenheimer expansion. A one-dimensional model of the H$_2^+$ molecule in a laser field shows the usefulness of the exact TDPES in interpreting coupled electron-nuclear dynamics: we show how features of its structure indicate the mechanism of dissociation. We compare the exact TDPES with potential energy surfaces from the time-dependent Hartree-approach, and also compare traditional Ehrenfest dynamics with Ehrenfest dynamics on the exact TDPES.

physics.chem-ph↗

arXiv2010

Exact factorization of the time-dependent electron-nuclear wavefunction

We present an exact decomposition of the complete wavefunction for a system of nuclei and electrons evolving in a time-dependent external potential. We derive formally exact equations for the nuclear and electronic wavefunctions that lead to rigorous definitions of a time-dependent potential energy surface (TDPES) and a time-dependent geometric phase. For the $H_2^+$ molecular ion exposed to a laser field, the TDPES proves to be a useful interpretive tool to identify different mechanisms of dissociation.

cond-mat.other↗