Domain dynamics and fluctuations in artificial square ice at finite temperatures
Domain dynamics and fluctuations in artificial square ice at finite temperatures
复制标题
DOI：
10.1088/1367-2630/14/3/035014
复制
发表时间：
2012-03-20
影响因子：
3.3
通讯作者：
Stamps, R. L.
中科院分区：
文献类型：
--
作者：
Budrikis, Z.;Livesey, K. L.;Stamps, R. L.
研究了方形人造自旋冰的热驱动顶点域的形成和演化。自洽平均场理论用于展示基态有序域如何自发形成，以及它们如何在无序存在的情况下演化。使用蒙特卡罗模拟和分析模型研究波动的作用。畴壁动力学被证明是由随机波动偏向收缩封闭域的过程驱动的，并且域内的波动被证明会产生孤立的小激励，随着有效温度的降低，这些激励可能会稳定下来。域动态和波动由相互作用强度决定，而相互作用强度由元素间间距控制。通过实验和蒙特卡罗模拟研究了相互作用强度的作用。我们的平均场模型适用于铁电“自旋”冰，并且我们表明可以预期与磁自旋冰类似的特征，但具有不同的特征温度和速率。
The thermally driven formation and evolution of vertex domains is studied for square artificial spin ice. A self-consistent mean-field theory is used to show how domains of ground state ordering form spontaneously, and how these evolve in the presence of disorder. The role of fluctuations is studied using Monte Carlo simulations and analytical modelling. Domain wall dynamics are shown to be driven by a biasing of random fluctuations towards processes that shrink closed domains, and fluctuations within domains are shown to generate isolated small excitations, which may stabilize as the effective temperature is lowered. Domain dynamics and fluctuations are determined by interaction strengths, which are controlled by inter-element spacing. The role of interaction strength is studied via experiments and Monte Carlo simulations. Our mean-field model is applicable to ferroelectric 'spin' ice, and we show that features similar to those of magnetic spin ice can be expected, but with different characteristic temperatures and rates.