Estructura i Constituents de la Matèria, Universitat de Barcelona, Avinguda Diagonal 647, 08028 Barcelona, Spain.
Phys Rev Lett. 2012 Nov 9;109(19):198304. doi: 10.1103/PhysRevLett.109.198304.
We study the collective dynamics of interacting paramagnetic colloids transported via a magnetic ratchet effect above a modulated periodic potential. Upon increasing the modulation frequency, the particles undergo a series of dynamic transitions, from a continuous smectic flow to a disorder flow, and later enter into a two phase flow regime, ending in a complete pinned state. In the disordered phase, the system organizes into density waves due to traffic jams, as in granular systems, while the two phase flow regime shows strong similarities with plastic flow in vortex matter. Finally, it is shown that induced attractive interactions between the moving colloids lead to enhancement of the particle current due to formation of condensed chains traveling along the modulated landscape.
我们研究了通过调制的周期性势上方的磁棘轮效应输运的相互作用顺磁胶体的集体动力学。随着调制频率的增加，粒子经历了一系列的动态转变，从连续的近晶流变为无序流，然后进入两相流状态，最终进入完全固定状态。在无序相中，由于交通堵塞，系统像在颗粒系统中一样组织成密度波，而两相流状态与涡旋物质中的塑性流有很强的相似性。最后，结果表明，由于沿调制地形形成凝聚链，运动胶体之间的感应吸引力相互作用导致粒子电流增强。
