Control of crystallization of solid He by acoustic radiation pressure and novel dynamics of quantum interface

我们观察到在声波作用下，S^4$He晶体中c面的快速生长。对于已知的台阶迁移率，生长速度不能用螺旋生长模型来解释。我们提出了一种新的高功率声波小面晶体生长机制。考虑声波振荡压力的一阶效应，将步长加速到声速的数量级。这种高速台阶的碰撞可以像Parshin和Tsymbalenko所说的那样引起台阶的倍增，并导致比螺旋生长更大的台阶密度。该模型很好地再现了观测到的功率与温度的关系，并与实验进行了定量的比较。

We observed the very fast growth of the c-facet of a S^4$He crystal induced by acoustic waves. The growth velocity cannot be explained by the spiral growth model for the known values of the step mobility. We developed a new crystal growth mechanism of the facet by high power acoustic waves. Considering the first order effect of the oscillating pressure of the acoustic wave, steps are accelerated to the order of the sound velocity. Collisions of such high speed steps can induce the multiplication of steps as Parshin and Tsymbalenko suggested and lead to the larger step density than that of the spiral growth. This model reproduces the observed power and temperature dependence well and also has a quantitative agreement with the experiment.