Energy landscape and rigidity
Abstract
The effects of floppy modes in the thermodynamical properties of a system are studied. From thermodynamical arguments, we deduce that floppy modes are not at zero frequency and thus a modified Debye model is used to take into account this effect. The model predicts a deviation from the Debye law at low temperatures. Then, the connection between the topography of the energy landscape, the topology of the phase space, and the rigidity of a glass is explored. As a result, we relate the number of constraints and floppy modes to the statistics of the landscape. We apply these ideas to a simple model for which we provide an approximate expression for the number of energy basins as a function of the rigidity. This helps to understand certain features of the glass transition, like the jump in the specific heat or the reversible window observed in chalcogenide glasses.
- Publication:
-
Physical Review E
- Pub Date:
- February 2005
- DOI:
- 10.1103/PhysRevE.71.026114
- arXiv:
- arXiv:cond-mat/0410484
- Bibcode:
- 2005PhRvE..71b6114N
- Keywords:
-
- 05.70.-a;
- 64.70.Pf;
- 64.60.-i;
- 05.65.+b;
- Thermodynamics;
- Glass transitions;
- General studies of phase transitions;
- Self-organized systems;
- Condensed Matter - Statistical Mechanics
- E-Print:
- 1 text+3 eps figures