Roughness-induced transport enhancement via non-equilibrium fluctuations

Understanding and controlling transport in systems far from thermal equilibrium is a fundamental goal in physics, biology, and nanotechnology. A canonical principle in this field is that landscape roughness almost universally acts as a detrimental factor that impedes particle motion and suppresses directed transport. Here, we challenge this paradigm by demonstrating that for particles driven by discrete non-equilibrium shot noise, engineered landscape roughness can act not as a dissipative obstacle, but as a constructive engine that enhances directed transport. This enhancement drives the particle to a velocity that significantly exceeds the free-particle limit-the average velocity resulting purely from the drive in the absence of a potential. We trace this effect to a novel dynamic mechanism we term unidirectional slide inhibition. Arising from a synergy between the potential’s global asymmetry and its local roughness, this mechanism effectively rectifies non-equilibrium fluctuations by selectively suppressing backward particle sliding. These findings establish a new principle for controlling transport via engineered disorder, opening new avenues for inspiring the design of more efficient nano-robots and providing new principles for particle-separation devices.