Curing ...
Dr. Neepa Maitra
Hunter College, New York
Lundi, 28 novembre 2011,
11h00 Bibliothèque 4e étage,
tour 12 - 13, site Jussieu
The theorems of Time-Dependent Density Functional Theory (TDDFT) hold
great promise for the description of real-time electron dynamics in
strong and weak fields. In principle, subtle electron correlation
effects in processes such as photodissociation dynamics,
non-sequential double-ionization, control of electron dynamics for
purposes such as selective bond cleavage, etc, can be exactly described.
However the approximate functionals available today suffer from
three major problems: the lack of memory in density-functional dependence,
the need for additional observable functionals to compute quantities such as
momentum-distributions, double-ionization probabilities, and
the extreme inaccuracy in describing situations where the true
wavefunction evolves far from any single-Slater determinant.
I will review these difficulties and present examples.
A new method has been recently proposed in which electron
correlation is evaluated by semiclassical Frozen Gaussian dynamics,
that ameliorates all three of these problems. Semiclassical
correlation is used to drive the one-body density-matrix time
evolution, all other terms of which are computed exactly.
I will describe the theory, and present results on some model systems.