International School for Advanced Studies (SISSA), Via Bonomea 265, 34136 Trieste, Italy.
CNR-IOM Democritos National Simulation Center, Via Bonomea 265, 34136 Trieste, Italy.
Phys Rev Lett. 2015 Mar 13;114(10):108302. doi: 10.1103/PhysRevLett.114.108302. Epub 2015 Mar 10.
Colloidal two-dimensional monolayers sliding in an optical lattice are of recent importance as a frictional system. In the general case when the monolayer and optical lattices are incommensurate, we predict two important novelties, one in the static equilibrium structure, the other in the frictional behavior under sliding. Structurally, realistic simulations show that the colloid layer should possess in full equilibrium a small misalignment rotation angle relative to the optical lattice, an effect so far unnoticed but visible in some published experimental moiré patterns. Under sliding, this misalignment has the effect of boosting the colloid monolayer friction by a considerable factor over the hypothetical aligned case discussed so far. A frictional increase of similar origin must generally affect other incommensurate adsorbed monolayers and contacts, to be sought out case by case.
胶体二维单层在光晶格中滑动作为摩擦系统是最近的研究热点。在单层和光晶格不相配的一般情况下，我们预测了两个重要的新颖性，一个在静态平衡结构中，另一个在滑动下的摩擦行为中。结构上，现实模拟表明胶体层在完全平衡时应该相对于光晶格具有一个小的失配旋转角，这一效应迄今为止尚未被注意到，但在一些已发表的实验莫尔图案中可见。在滑动下，这种失配会使胶体单层的摩擦力相对于迄今为止讨论的假设对齐情况显著增加一个相当大的因子。类似来源的摩擦力增加通常会影响其他不相配的吸附单层和接触，需要逐个案例寻找。
