Critical fluctuations of time-dependent magnetization in a random-field Ising model

Hiroki Ohta; Shin-ichi Sasa

doi:10.1103/physreve.77.021119

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arXiv · 0706.3629

Critical fluctuations of time-dependent magnetization in a random-field Ising model

Hiroki Ohta·Shin-ichi Sasa

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Abstract

Cooperative behaviors near the disorder-induced critical point in a random field Ising model are numerically investigated by analyzing time-dependent magnetization in ordering processes from a special initial condition. We find that the intensity of fluctuations of time-dependent magnetization, $\chi(t)$, attains a maximum value at a time $t=\tau$ in a normal phase and that $\chi(\tau)$ and $\tau$ exhibit divergences near the disorder-induced critical point. Furthermore, spin configurations around the time $\tau$ are characterized by a length scale, which also exhibits a divergence near the critical point. We estimate the critical exponents that characterize these power-law divergences by using a finite-size scaling method.

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BibTeX RIS

Hiroki Ohta, Shin-ichi Sasa. 2007-06-25. Critical fluctuations of time-dependent magnetization in a random-field Ising model. https://doi.org/10.1103/physreve.77.021119

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