论文标题
双稳定电势中的单文件扩散：在标记粒子的屏障交叉中记忆的特征
Single-file diffusion in a bi-stable potential: signatures of memory in the barrier-crossing of a tagged-particle
论文作者
论文摘要
我们研究在过度阻尼的环境中屏障横断的记忆效应。我们专注于隐藏的自由度在与可观察的时间尺度完全相同的时间尺度上放松的情况。作为一个原型模型，我们分析了一个局限于双稳定电势的单个文件中标记的粒子扩散。我们确定记忆的签名并解释其起源。新兴的记忆是集体多体征原模式投影到标记粒子运动的结果。我们对“限制”（标记粒子前面的所有背景粒子）和“推动”（标记粒子背后的所有背景粒子）情景感兴趣，我们发现这些场景是我们发现的非平凡和定性不同的放松行为。值得注意的是，出乎意料的是，在固定的粒子数下，我们发现屏障越高，记忆效应越强。外部电势会改变内存的事实更为重要，应在广义Langevin方程的应用中考虑到。我们的结果很容易通过实验测试，并且可能与了解生物离子通道中的运输有关。
We investigate memory effects in barrier-crossing in the overdamped setting. We focus on the scenario where the hidden degrees of freedom relax on exactly the same time scale as the observable. As a prototypical model, we analyze tagged-particle diffusion in a single file confined to a bi-stable potential. We identify the signatures of memory and explain their origin. The emerging memory is a result of the projection of collective many-body eigenmodes onto the motion of a tagged-particle. We are interested in the "confining" (all background particles in front of the tagged-particle) and "pushing" (all background particles behind the tagged-particle) scenarios for which we find non-trivial and qualitatively different relaxation behaviors. Notably and somewhat unexpectedly, at a fixed particle number, we find that the higher the barrier, the stronger the memory effects are. The fact that the external potential alters the memory is important more generally and should be taken into account in applications of generalized Langevin equations. Our results can readily be tested experimentally and may be relevant for understanding transport in biological ion-channels.
