Organisers

• Angel Rubio (Departamento Fisica de Materiales, Facultad de Quimicas, Universidad del Pais Vasco)

Supports

 CECAM

 Marie Curie Actions - Psi-k Training

Description

Time-dependent density-functional theory (TDDFT) is an extension of density functional theory (DFT) to time-dependent problems, and can be viewed as an alternative formulation of time-dependent quantum mechanics. As in DFT, the wave-function no longer has the leading role: the basic variable of TDDFT is the one-body electron density, n(r,t). The advantages are clear: a complex function in 3N-dimensional space (where N is the number of electrons in the system) - the many-body wave-function - is replaced by a real function that depends solely on the 3-dimensional vector r - the density. Usually n(r,t) is obtained using an auxiliary system of non-interacting electrons that feel an effective time-dependent potential, the time-dependent Kohn-Sham potential. Its exact form is, however, unknown, and has to be approximated.

The use of TDDFT is increasing, and it is fast becoming one of the tools of choice to get accurate and reliable predictions for excited-state properties in solid state physics, chemistry and biophysics, both in the linear and non-linear regimes. This interest has been motivated by the recent developments of TDDFT (and time-dependent current functional theory) and include the description of photo-absorption cross section of molecules and nanostructures, electron-ion dynamics in the excited state triggered by either a small or high intense laser fields, van der Waals interactions, development of new functionals coping with memory and non-locality effects, applications to biological systems (chromophores), transport phenomena, optical spectra of solids and low-dimensional structures (as nanotubes, polymers, surfaces...).

Despite the rising interest in the calculation of excited state properties of quantum systems, the techniques being used have usually been just one of the topics covered in international meetings, schools and workshops. This means that scientists new to the field face difficulties in grasping its many aspects that could be alleviated if they could attend a school on time-dependent density functional theory TDDFT or Many-Body Techniques (MBT). We also believe that a school on these techniques would be extremely helpful for young graduate students, post-docs and even older scientists that are envisaging a project for which TDDFT/MBT would be the tool of choice. For this reason we decided to organize a set of schools and workshops on these techniques, covering its theoretical, practical, and numerical aspects. The first one was done in Benasque in 2004 (see history above).

Following our previous experience, we are convinced that the most efficient scheme for training of young researchers in these techniques is to have a school where the basic theory is taught followed by a workshop that introduces them to the forefront research in the field. The school should have an equal share of theoretical and practical classes. This would ease the learning of the techniques and would provide the students with the practical knowledge of the numerical aspects and difficulties, while also introducing them to well-established open source numerical codes. At the end of the school, students should have sufficient working knowledge to pursue their projects at their home institution.

The school will be followed by an international workshop, where the new developments of TDDFT and Many-Body Techniques for the calculation of excitations will be discussed. Students attending the school will be encouraged to attend the workshop, so they can get in contact with state of the art research in the field. The purpose of the workshop is to bring together leading experts in all these fields with different backgrounds, like density functional, many-body, nuclear physics and quantum chemists. This will allow the exchange of ideas between the different fields and the creation of links between the traditionally separated communities. We believe that the intense and informal discussion which is possible in this kind of workshops can contribute to the formation of a strong community in the field of TDDFT.

Tentative program for the school:

--------------------------------

The school will be attended by a maximum of around 40 students, and will last 10 days, with theoretical sessions (mostly) in the mornings and practical
(tutorial) sessions in the afternoons. The theoretical sessions will consist of two 1.5h lectures (divided in two 45m sessions including discussions). The practical sessions will last for 3 hours and a computer will be
allocated for each two students. This will allow the students to have some
time every day for studying and talking to the teachers.
The program of the school starts with basic TDDFT, then continues with more complex theoretical and numerical aspects of TDDFT, and will end with an outline of some of its many applications. Basic knowledge on ground state DFT calculations is required. Also during the school we will address other approaches to describe excite state properties based on either many-body perturbation theory or quantum-chemistry schemes.