Exploring the dynamic responses of a material is of importance to both understanding its fundamental physics at high frequencies and potential device applications. Here we develop a phase-field model for predicting the dynamics of ferroelectric materials and study the dynamic responses of ferroelectric domains and domain walls subjected to an ultrafast electric field pulse. We discover a transition of domain evolution mechanisms from pure domain growth at a relatively low field to combined nucleation and growth of domains at a high field. We derive analytical models for the two regimes which allow us to extract the effective mass and damping coefficient of ferroelectric domain walls. The exhibition of two regimes for the ferroelectric domain dynamics at low and high electric fields is expected to be a general phenomenon that would appear for ferroic domains under other ultrafast stimuli. The present work also offers a general framework for studying domain dynamics and obtaining fundamental properties of domain walls and thus for manipulating the dynamic functionalities of ferroelectric materials.

中文翻译：

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超快速电场脉冲下的域动力学

探索材料的动态响应对于理解高频下的基本物理原理和潜在的设备应用都至关重要。在这里，我们建立了一个预测铁电材料动力学的相场模型，并研究了铁电畴和畴壁在超快电场脉冲作用下的动态响应。我们发现域演化机制从相对低场的纯域增长到高场域的结合成核和域增长的过渡。我们导出了这两种情况的分析模型，这使我们能够提取铁电畴壁的有效质量和阻尼系数。在低电场和高电场下，铁电畴动力学的两种表现形式有望成为普遍现象，在其他超快刺激下，铁电畴会出现这种现象。本工作还为研究磁畴动力学和获得磁畴壁的基本特性，从而操纵铁电材料的动力学功能提供了一个通用框架。