Mulhern C
Max Planck Institute for the Physics of Complex System, 01187 Dresden, Germany.
Phys Rev E Stat Nonlin Soft Matter Phys. 2013 Aug;88(2):022906. doi: 10.1103/PhysRevE.88.022906. Epub 2013 Aug 7.
For systems out of equilibrium and subjected to a static bias force it can often be expected that particle transport will usually follow the direction of this bias. However, counterexamples exist where particles exhibit uphill motion (known as absolute negative mobility, ANM), particularly in the case of coupled particles. Examples in single particle deterministic systems are less common. Recently, in one such example, uphill motion was shown to occur for an inertial driven and damped particle in a spatially symmetric periodic potential. The source of this anomalous transport was a combination of two periodic driving signals which together are asymmetric under time reversal. In this paper we investigate the phenomena of ANM for a deterministic particle evolving in a periodic and symmetric potential subjected to an external unbiased periodic driving and nonuniform space-dependent damping. It will be shown that this system exhibits a complicated response behavior as certain control parameters are varied, most notably being enhanced parameter regimes exhibiting ANM as the static bias force is increased. Moreover, the solutions exhibiting ANM are shown to be, at least over intermediate time periods, superdiffusive, in contrast to the solutions that follow the bias where the diffusion is normal.
对于处于非平衡状态且受到静态偏置力作用的系统，通常可以预期粒子输运通常会沿着该偏置的方向进行。然而，存在反例，即粒子表现出向上运动（称为绝对负迁移率，ANM），特别是在耦合粒子的情况下。单粒子确定性系统中的例子则较少见。最近，在一个这样的例子中，已表明在空间对称的周期势中，惯性驱动和阻尼的粒子会出现向上运动。这种反常输运的根源是两个周期驱动信号的组合，它们在时间反演下共同不对称。在本文中，我们研究了在周期性和对称势中演化的确定性粒子的ANM现象，该粒子受到外部无偏周期驱动和非均匀空间相关阻尼的作用。结果表明，随着某些控制参数的变化，该系统表现出复杂的响应行为，最显著的是当静态偏置力增加时，会出现增强的参数区域表现出ANM。此外，与遵循偏置且扩散为正常的解相比，表现出ANM的解至少在中间时间段内是超扩散的。
