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Scientific Report 2007-2009
Condensed matter physics and biophysics
C38. Nonlinear electrodynamics in complex disordered systems: the
SolarPaint project
The SolarPaint project is an interdisciplinary research
aimed at mastering the link between complexity
and light trapping mechanism in disordered systems,
fostering new applications in the field of energy and
medicine, as well as novel fundamental discoveries
in applied mathematics and the science of complex
systems. The project involves mathematical physics
(solitons, shock waves, group theory, Lie algebras and
symmetries of partial differential equations), theoretical
physics (thermodynamics of chaos, statistical mechanics
of disordered systems) and ab-initio computational
science.
The term ”ab-initio” means ”from first principles, with
no approximation” and identifies numerical integration
schemes aimed at investigating phenomena stemming
from first-principle equations of motion. The computational
activity of SolarPaint is devoted to the realization
of advanced parallel codes for the analysis of light
propagation in disordered materials characterized by
various wavelengths, ranging from the Angstrom regime
to the visible, Terahertz and the acoustic scale. With
reference to these different domains, the mathematical
and theoretical portion of the project involves the study
of:
X-ray Free Electron Laser (XFEL) beams interaction
with molecular matter. XFEL are revolutionary photons
sources, whose ultrashort, brilliant pulses are expected
to allow single molecule diffraction experiments with
interatomic length scales and femtosecond time resolutions.
Statistical description of a many-body solitons systems.
A system of interacting solitons do exhibit interesting
complex phenomena such as the generation of dispersive
shocks and rogue waves. In the project we derive advanced
theories able to provide simple thermodynamic
interpretations of these phenomena.
Anderson localization of light. One of the most interesting
effects of disorder is the trapping of light and
the emergence of long living localized states, known
as Anderson localizations, here studied in different
configurations.
Disordered optical cavities. These systems do exhibit
interesting links with spin-glasses with quenched disorder
and the field of random matrices, here employed to
provide a new perspective on these media.
Disordered photonic crystals and photon-plasmon
polariton interactions. By exploiting interactions with
photons and plasmon-polaritons in disordered photonic
crystals, we study new concentrators for electromagnetic
radiation in the terahertz regime for fundamental
astrophysical studies.
Structural glasses, self assembly of dielectric scatterers.
An important part of the project will be devoted to
the study of the self-assembly properties of materials;
an open problem, in fact, is how to realize a mean
configuration of disorder necessary to observe, e.g. a
specific property or a particular dynamics. To deal
with this issue we here study self-assembled ”photonic”
colloids, in which optical components are first dispersed
Figure 1: Ab-initio simulation showing the far-field scattered
angular pattern (red to yellow colormap), nuclei position and
electron density (blu to yellow colormap) time evolution of
an HNCO molecule irradiated by an ultrashort XFEL pulse.
Figure 2: Intensity |ψ| 2 , and frequency S x evolution of an
ensemble of solitons originating a dispersive shock at t sk =
0.0135.
in a host medium and then assembled through the
equilibrium configuration of the system.
References
1. A. Fratalocchi et al., Phys. Rev. Lett. 101, 044101
(2008).
2. A. Fratalocchi et al., Phys. Rev. B 77, 245132 (2008)
3. A. Fratalocchi et al., Phys. Rev. A 78, 013806 (2008)
4. C. Conti et al., Nature Physics, 4 794 (2008)
Authors
A. Fratalocchi, G. Ruocco
http://www.solarpaintproject.org/
Sapienza Università di Roma 91 Dipartimento di Fisica