在多层 Ising 模型系统的动态相变中的关键行为交叉
Erol Vatansever1, Mikel Quintana2, Andreas Berger2
1Dokuz Eylül University, Department of Physics, TR-35160, Izmir-Turkey.
Physical review. E
|November 18, 2025
概括
本研究探讨了铁磁薄膜在动态相变 (DPT) 中的关键行为交叉. 较薄的薄膜表现出2D特征,而较厚的薄膜表现出3D行为,DPT交叉发生在比热力学相变 (TPT) 更大的厚度.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学 材料科学 材料科学
- 统计力学 统计力学
背景情况:
- 铁磁薄膜表现出由维度和表面效应影响的复杂的关键现象.
- 了解动态相变 (DPT) 和热力学相变 (TPT) 对材料应用至关重要.
- 维度交叉,从2D到3D行为的过渡,是薄膜系统中的一个关键现象.
研究的目的:
- 在动态相位转换 (DPT) 下的铁磁薄膜中研究关键行为的维度交叉.
- 为了将DPT的交叉行为与热力学相变 (TPT) 作为薄膜厚度的函数进行比较.
- 基于几何学和表面效应来解释不平衡系统中不同的缩放规律和关键行为.
主要方法:
- 利用动力Ising模型的蒙特卡洛模拟来研究铁磁薄膜.
- 专注于在依赖时间的外部磁场下的动态顺序参数的缩放行为.
- 分析了从二维到三维的关键行为的过渡,作为薄膜厚度和接近关键点的函数.
主要成果:
- 观察到缩放行为的明显转变,较薄的薄膜显示2D类,较厚的薄膜显示3D类特征,无论是DPT还是TPT.
- 发现,与TPT相比,DPT的2D到3D交叉发生在较大的薄膜厚度.
- 结果与在超薄Co.膜中不同动态和热力学临界指数的实验观测结果一致.
结论:
- 铁磁薄膜中的动态和热力学相变由不同的长度尺度和表面效应控制.
- 薄膜几何学显著影响平衡和不平衡系统中的缩放规律和关键行为.
- 该研究为时间依赖磁场中的关键现象提供了全面的解释,协调了模拟和实验数据.
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