论文标题
在振荡的谐波陷阱阵列中增强分散体
Enhanced dispersion in an oscillating array of harmonic traps
论文作者
论文摘要
实验，理论和模拟用于了解胶体颗粒在光学镊子产生的周期性振荡谐波陷阱中的分散。在陷阱振荡的情况下，观察到非单调和各向异性分散体。出乎意料的是，最僵硬的陷阱在临界频率下产生最大的色散，并且颗粒在振荡方向上的扩散速度明显快于那些接受被动Stokes-Einstein-Sutherland扩散的颗粒。使用广义泰勒分散理论和布朗动力学模拟开发了颗粒有效扩散率随陷阱刚度和振荡频率的函数的理论预测。理论和模拟都表现出与实验的极好的一致性，并揭示了一种新的``slingshot''机制，该机制可以预测动态外部场中胶体扩散的显着增强。
Experiment, theory, and simulation are employed to understand the dispersion of colloidal particles in a periodic array of oscillating harmonic traps generated by optical tweezers. In the presence of trap oscillation, a non-monotonic and anisotropic dispersion is observed. Surprisingly, the stiffest traps produce the largest dispersion at a critical frequency, and the particles diffuse significantly faster in the direction of oscillation than those undergoing passive Stokes-Einstein-Sutherland diffusion. Theoretical predictions for the effective diffusivity of the particles as a function of trap stiffness and oscillation frequency are developed using generalized Taylor dispersion theory and Brownian dynamics simulations. Both theory and simulation demonstrate excellent agreement with the experiments, and reveal a new ``slingshot'' mechanism that predicts a significant enhancement of colloidal diffusion in dynamic external fields.
