Ultra-fast phenomena in quantum physics: a challenge for theory & experiment
CECAM-HQ-EPFL, Lausanne, Switzerland
With the advent of nanoscale physics and ultrafast lasers it is now possible to directly probe real-time the correlation betw een particles in excited quantum states [1-7]. In addition it is now possible to control and manipulate the opto-electronic properties of a wide range of materials by tuning the properties of the external laser field, see e.g. Refs.[8-11].
Experimental and theoretical activities on this topic have opened new fields of research like, e.g., molecular transport , nanoelectronics [13-14], attosecond physics , nonequilibrium phase transitions , ultracold atomic gases in optical traps , optimal control theory , kinetics of Bose condensates , etc.
Nevertheless, despite the massive number of available experimental results there are still scarce numerical and theoretical methods in use of the scientific community. The fast development of new characterization techniques and the production of stable nanoscale materials have not been followed by a similar evolution of the theoretical tools.
Experiments are usually carried on systems, such as nanostructures and biological systems, that are formed by hundreds/thousands of atoms, see e.g. Refs. [19-21], and their peculiar properties are related to their reduced dimensionality and extended surface. Any reliable theory is inevitably linked to a detailed knowledge of their structural and dynamical properties. Due to the complexity of these systems, however, state-of-the art methods are either confined to simple models with empirical parameters, thus depriving the theory of its predictive aspiration, or based on Density Functional Theory (DFT) at the level of adiabatic-local approximations , thus ruling out the possibility of describing correctly excitonic effects, relaxation processes and other key aspects of the non-equilibrium dynamics.
Although improvements of the DFT functionals are currently an active area of research, an alternative to adiabatic-local DFT based on the density-matrix and Green’s function formalism is emerging [23-25]. These formalisms are two of the most powerful and versatile in physics, and have already been proved to be extremely useful in several other contexts. Still the communities working with different methods remain fragmented and, often, not in contact among themselves and with the experimentalists. In this way theoretical advances are slowed down and the possibility of inspiring new experiments and practical applications is jeopardize. This situation is unavoidably creating a gap between theory and experiment.
The goal of this workshop is, indeed, to gather together many of the most prominent theoretical and experimental scientists. Discussions will be stimulated during the long slots following each talk (around 20 minutes) and round tables.
Cristian Manzoni (IFN-CNR Dipartimento di Fisica, Politecnico di Milano) - Organiser
Andrea Marini (CNR) - Organiser
Deborah Prezzi (National Research Council) - Organiser
Gianluca Stefanucci (University of Rome Tor Vergata) - Organiser