Extended Fluctuation-Dissipation Theorem for Driven Colloidal Suspensions

涨落耗散定理在计算机模拟中广泛应用于输运性质的计算，具有重要的实际意义和重要的理论意义。到目前为止，这些计算主要局限于平衡态。在第一个资助期内，我们展示了如何将涨落耗散定理推广到只涉及可测量量的非平衡稳态。基于这一结果，我们将研究一个由简单剪切流驱动的非平衡胶体悬浮液模型。我们将检验用“有效温度”来简单描述的可行性。将确定流动诱导的颗粒间水动力相互作用对这些新的涨落-耗散关系的影响。作为一个具体的应用，我们将制备一种只可能在非平衡状态下存在的特殊状态——剪切熔化悬浮，并通过我们的广义涨落耗散定理研究单粒子扩散和迁移率的相互作用。

The fluctuation-dissipation theorem is both of great practical importance for the calculation of transport properties from computer simulations in a wide range of applications as well as of fundamental theoretical interest. So far these calculations have been mainly restricted to equilibrium. During the first funding period we have shown how to extend the fluctuation-dissipation theorem to non-equilibrium steady states involving only measurable quantities. Based on this result we will study a model colloidal suspension driven into non-equilibrium by simple shear flow. We will test to which extent a simple description in terms of an „effective temperature“ is feasible. The influence of flow-induced hydrodynamic interactions between particles on these new fluctuation-dissipation relations will be determined. As a concrete application we will prepare a special state which is only possible in non-equilibrium – a shear-melted suspension – and study the interplay of single-particle diffusion and mobility through our generalized fluctuation-dissipation theorem.