The spin glasses are disordered and frustrated magnetic systems. They show aging phenomena which are also a characteristic feature of structural glasses, polymers, dielectrics, colloids, etc. Under a strong enough magnetic field variation, spin glasses can be "rejuvenated", in the same way as glasses under a high enough stress. But spin glasses also display non-trivial "rejuvenation and memory" effects when they are submitted to temperature variations. Comparable phenomena have recently been identified in some polymers and gels, although less sharply pronounced. We propose to describe aging phenomena in disordered systems in terms of a combination of such "temperature-selective" effects with the more usual "temperature-cumulative" processes related to strong cooling rate effects.
- Pub Date:
- May 2002
- Condensed Matter - Disordered Systems and Neural Networks;
- Condensed Matter - Materials Science
- Paper in french, to appear in the Proceedings of the conference "Materiaux 2002", Tours (France) October 2002. 1 pdf file, 4 pages