论文标题
具有显微可逆机制的活性颗粒的扩散系数和功率谱
Diffusion coefficient and power spectrum of active particles with a microscopically reversible mechanism of self-propelling
论文作者
论文摘要
催化活性的大分子被认为是人工纳米运动的关键构件。但是,理论和实验报告了有关其动态的矛盾发现。缺乏共识主要是由于对纳米级自我推广机制的细节的有限理解引起的。在这里,我们研究了不依赖特定机制的自行纳米颗粒的通用模型。相反,其主要假设是化学反应微观动力学的基本对称性:微观可逆性的原理。如果我们将粒子承受外部时间周期力的作用,则会产生这种假设的重大后果。与公正的动力学相比,粒子扩散系数随后增强。增强功能可以通过力振幅和频率控制。我们还得出了粒子轨迹的功率谱。在来自显微镜可逆性的新效果中,在所有频率和乙状结肠形的过渡和旋转扩散和外部强迫的特征频率下峰的增强。显微镜可逆性是广泛的化学反应的通用特性,因此,我们期望提出的结果将激发旨在测试我们预测的新实验研究。这可以为催化大分子动力学提供新的见解。
Catalytically active macromolecules are envisioned as key building blocks in development of artificial nanomotors. However, theory and experiments report conflicting findings regarding their dynamics. The lack of consensus is mostly caused by a limited understanding of specifics of self-propulsion mechanisms at the nanoscale. Here, we study a generic model of a self-propelled nanoparticle that does not rely on a particular mechanism. Instead, its main assumption is the fundamental symmetry of microscopic dynamics of chemical reactions: the principle of microscopic reversibility. Significant consequences of this assumption arise if we subject the particle to an action of an external time-periodic force. The particle diffusion coefficient is then enhanced compared to the unbiased dynamics. The enhancement can be controlled by the force amplitude and frequency. We also derive the power spectrum of particle trajectories. Among new effects stemming from the microscopic reversibility are the enhancement of the spectrum at all frequencies and sigmoid-shaped transitions and a peak at characteristic frequencies of rotational diffusion and external forcing. The microscopic reversibility is a generic property of a broad class of chemical reactions, therefore we expect that the presented results will motivate new experimental studies aimed at testing of our predictions. This could provide new insights into dynamics of catalytic macromolecules.