Relaxation Times Obtained From Dynamical Decay Function of 1D and 3D Ising Model

Abstract

We calculated the dynamical decay of the autocorrelation function of 1D and 3D systems of Ising spins. The calculations were performed by Monte Carlo method for different size domains and at different temperature. Analyzing autocorrelation functions for a transition mechanism, when spin flip dynamics depends on initial energy before the flip only, two main relaxation times were distinguished for each size. When dynamics depends on energy difference before and after the flip, only one relaxation time, (corresponding to the main mode) which depends on domain size, is obtained. These results strongly suggest that non-Debye relaxation in dipolar glasses and relaxors might be caused by domain size distribution.

Keywords:

• Ising model
• Monte Carlo method
• autocorrelation function
• distribution of relaxation times

Acknowledgment

This work was supported by the project MULTIMA (No C-18/2007) of Lithuanian State Science Foundation.

Notes

¹ Time is presented in Monte Carlo steps per site (MCS/s).