Defect fluctuations and lifetimes in disordered Yukawa systems

Area of Science:

• Physics
• Materials Science
• Soft Matter Physics

Background:

• Disordered systems, such as granular materials and colloids, exhibit complex dynamics.
• Topological defects play a crucial role in the behavior of these systems.
• Understanding defect dynamics is key to characterizing the phase transitions and emergent properties of disordered matter.

Purpose of the Study:

• To investigate the time-dependent defect fluctuations and coordination number lifetimes in a bidisperse disordered assembly of Yukawa particles.
• To analyze how temperature influences the spectral properties of defect fluctuations and the distribution of coordination number lifetimes.
• To explore the potential of topological defect fluctuations as a metric for characterizing disordered systems.

Main Methods:

• Simulations of a bidisperse disordered assembly of Yukawa particles.
• Analysis of noise spectra of defect fluctuations at different temperatures.
• Examination of coordination number lifetime distributions.

Main Results:

• At high temperatures, defect fluctuations exhibit a white noise spectrum, and coordination number lifetimes follow a stretched exponential distribution.
• At low temperatures, the system undergoes dynamic freezing, characterized by defect fluctuations showing a 1/f spectrum.
• Coordination number lifetimes at low temperatures follow a power law distribution.

Conclusions:

• Topological defect fluctuations exhibit distinct spectral characteristics (white noise vs. 1/f noise) corresponding to different dynamical regimes (high temperature vs. low temperature/dynamic freezing).
• The distribution of coordination number lifetimes transitions from stretched exponential to power law with decreasing temperature, reflecting changes in system dynamics.
• Topological defect fluctuations serve as a valuable indicator for characterizing the dynamic states and phase behavior of disordered systems.