Table of Contents
Physics Research International
Volume 2013 (2013), Article ID 236743, 8 pages
http://dx.doi.org/10.1155/2013/236743
Research Article

Molecular Tomography of the Quantum State by Time-Resolved Electron Diffraction

Moscow Lomonosov State University of Fine Chemical Technologies, Vernadskogo prosp. 86, Moscow 119589, Russia

Received 18 March 2013; Revised 11 July 2013; Accepted 14 October 2013

Academic Editor: Ashok Chatterjee

Copyright © 2013 A. A. Ischenko. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A procedure is described that can be used to reconstruct the quantum state of a molecular ensemble from time-dependent internuclear probability density functions determined by time-resolved electron diffraction. The procedure makes use of established techniques for evaluating the density matrix and the phase-space joint probability density, that is, the Wigner function. A novel expression for describing electron diffraction intensities in terms of the Wigner function is presented. An approximate variant of the method, neglecting the off-diagonal elements of the density matrix, was tested by analyzing gas electron diffraction data for N2 in a Boltzmann distribution and TRED data obtained from the 193 nm photodissociation of CS2 to carbon monosulfide, CS, at 20, 40, and 120 ns after irradiation. The coherent changes in the nuclear subsystem by time-resolved electron diffraction method determine the fundamental transition from the standard kinetics to the dynamics of the phase trajectory of the molecule and the tomography of molecular quantum state.