Slow relaxation phenomena in nonlinear systems with breathers

Project Information

Grant agreement ID: FMBI972237

Project closed

Start date 1 October 1997

End date 31 December 1997

Funded under

• Specific research and technological development programme in the field of the training and mobility of researchers, 1994-1998

Total cost € 0,00

EU contribution No data

Coordinated by

CONSEJO SUPERIOR DE INVESTIGACIONES CIENTIFICAS
Spain

Objective

Research objectives and content
The slow relaxation phenomena observed in glasses are usually interpreted by the existence of many metastable states. George Tsironis and I have recently shown that nonlinear systems without metastable states, may also exhibit similar behaviours. We have also shown that this unexpected feature is essentially a consequence of the property that these systems can sustain long life time breathers (Nonlinear Localized Excitations) which play a role similar to those of metastable states. On the base of the new developments of the theory of breathers to which I participated actively, I propose to collaborate with the group of George Tsironis in Heraklion for performing a detailed analysis of the phenomena in 1 and 2 dimensional models. We shall analyse its consequences on the thermal transport and the dynamical response function of these systems. We shall also study the possibility of defining extended diffusion equations (similar to those used for porous media) which could describe these phenomena. The connection with the famous FPU (Fermi-Pasta-Ulam) numerical experiments showing a poor thermalisation in some anharmonic systems, shall be also investigated. We shall also study the possibility of realizing real experiments exhibiting such slow thermal relaxation for example by probing as a function of time, the relaxation of a thermal grid in appropriate anharmonic materials created by the interference of two short laser pulses.
Training content (objective, benefit and expected impact)
I have been recently involved in the recent breakthrough on the theory of breathers (existence proof in large classes of anharmonic models and other rigorous results). I collaborated recently with George Tsironis for the initial stage of this program. The purpose of the collaboration is to involve PHD students and post-doctoral physicists of Heraklion in this research program.

Fields of science

• engineering and technology › materials engineering
• natural sciences › physical sciences › optics › laser physics

Programme(s)

• FP4-TMR - Specific research and technological development programme in the field of the training and mobility of researchers, 1994-1998

Topic(s)

• 0302 - Post-doctoral research training grants
• TP07 - Statistical Physics

Call for proposal

Data not available

Funding Scheme

RGI - Research grants (individual fellowships)

Coordinator

CONSEJO SUPERIOR DE INVESTIGACIONES CIENTIFICAS

• EU contribution: No data
• Address: 08193 Bellaterra ; Spain
• Total cost: No data