Reichhardt C, Olson C J
Center for Nonlinear Studies and Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Phys Rev Lett. 2002 Jun 17;88(24):248301. doi: 10.1103/PhysRevLett.88.248301. Epub 2002 May 31.
We show, using numerical simulations, that a rich variety of novel colloidal crystalline states are realized on square and triangular two-dimensional periodic substrates which can be experimentally created using crossed-laser arrays. When there are more colloids than potential substrate minima, multiple colloids are trapped at each substrate minima and act as a single particle with a rotational degree of freedom, giving rise to a new type of orientational order. We call these states colloidal molecular crystals. A two-step melting can also occur in which individual colloidal molecules initially rotate, destroying the overall orientational order, followed by the onset of interwell colloidal hopping.
我们通过数值模拟表明，在正方形和三角形二维周期性衬底上可以实现多种新型胶体晶体状态，这些衬底可以利用交叉激光阵列通过实验创建。当胶体数量多于潜在衬底极小值时，多个胶体被困在每个衬底极小值处，并作为具有旋转自由度的单个粒子起作用，从而产生一种新型的取向有序。我们将这些状态称为胶体分子晶体。还可能发生两步熔化过程，其中单个胶体分子最初旋转，破坏整体取向有序，随后发生阱间胶体跳跃。
