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Relaxation time in disordered molecular systems.

Rodrigo P Rocha1, José A Freire2

  • 1Departamento de Física, Universidade Federal de Santa Catarina, 88040-900 Florianópolis-SC, Brazil.

The Journal of Chemical Physics
|June 1, 2015
PubMed
Summary
This summary is machine-generated.

System disorder significantly increases relaxation time, the duration for a system to reach thermal equilibrium. This effect was observed in an amorphous molecular model, showing disorder

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Area of Science:

  • Condensed matter physics
  • Statistical mechanics
  • Materials science

Background:

  • Thermal equilibrium is a fundamental concept in physics, describing the state where a system's macroscopic properties are constant.
  • Relaxation time quantifies the rate at which a system approaches thermal equilibrium after a perturbation.
  • System disorder, such as in amorphous materials, is hypothesized to influence relaxation dynamics.

Purpose of the Study:

  • To derive an analytical expression for the dependence of relaxation time on system disorder.
  • To investigate the role of disorder in electronic equilibration within amorphous molecular systems.
  • To determine if initial state conditions affect relaxation time in disordered systems.

Main Methods:

  • Development of a simplified analytical model for electronic equilibration in amorphous molecular systems.
  • Mathematical derivation of the relationship between system disorder and relaxation time.
  • Analysis of the model's predictions regarding initial state independence.

Main Results:

  • A clear analytical expression demonstrating the enhancement of relaxation time by system disorder was derived.
  • Disorder was found to dramatically increase the relaxation time required to reach thermal equilibrium.
  • The nature of the initial state was shown to have no impact on the relaxation time.

Conclusions:

  • System disorder is a critical factor significantly prolonging relaxation times in amorphous molecular systems.
  • The derived analytical expression provides a quantitative understanding of disorder's effect on equilibration.
  • The findings highlight the robustness of relaxation dynamics concerning initial conditions in these disordered systems.