Optical trapping and critical Casimir forces

通过临界Casimir力捕获化学条纹附近的胶体

Trapping colloids near chemical stripes via critical Casimir forces

我们从理论和实验上研究了溶剂介导的临界Casimir力作用于胶体颗粒浸没在水和2，6-二甲基吡啶的二元液体混合物和接近基板的化学图案与周期性交替条纹的拮抗吸附偏好。这些图案通过微接触印刷实验实现。在接近溶剂的临界分层点时，法向和侧向临界Casimir力产生用于胶体的侧向限制有效势。我们详细分析了接近这种基板的球形胶体的丰富的行为。对于我们研究的所有图案化衬底，我们对这些有效电势的测量与相应的理论预测一致。由于临界Casimir力的方向和强度都可以通过微小的温度变化来调整，这为控制胶体作为模型系统提供了一种新的机制，为应用开辟了令人鼓舞的前景。

平面与锯齿面间的临界Casimir力

Critical Casimir forces between planar and crenellated surfaces

我们在平均场论中研究了平面壁与几何结构基底之间的临界Casimir力.作为基板结构，垛口表面组成的矩形垛口和城齿的周期性阵列被认为是。在广泛使用的邻近力近似中，城齿的顶表面和垛口的底表面都对临界卡西米尔力有贡献。然而，对于这样的系统的完整的，数值确定的临界Casimir力偏离显着从成对加法formalismunderlying邻近力近似。一阶修正的邻近力近似提出的一个步骤的贡献所产生的临界Casimir之间的相互作用的平面基板和直角的城齿的步骤，包括它们的上，下边缘，以及它们的侧壁。

Casimir effect between pinned particles in two-dimensional jammed systems

The Casimir effect arises when long-ranged fluctuations are geometrically confined between two surfaces, leading to a macroscopic force. Traditionally, these forces have been observed in quantum systems and near critical points in classical systems. Here we show the existence of Casimir-like forces between two pinned particles immersed in two-dimensional systems near the jamming transition. We observe two components to the total force: a short-ranged, depletion force and a long-ranged, repulsive Casimir-like force. The Casimir-like force dominates as the jamming transition is approached, and w…

Tunable critical Casimir forces counteract Casimir-Lifshitz attraction

Casimir forces in quantum electrodynamics emerge between microscopic metallic objects because of the confinement of the vacuum electromagnetic fluctuations occurring even at zero temperature. Their generalization at finite temperature and in material media are referred to as Casimir--Lifshitz forces. These forces are typically attractive, leading to the widespread problem of stiction between the metallic parts of micro- and nanodevices. Recently, repulsive Casimir forces have been experimentally realized but their reliance on specialized materials prevents their dynamic control and thus limits…

三临界点上的Casimir力：理论和可能的实验

Casimir Forces at Tricritical Points: Theory and Possible Experiments

利用场论方法和利用共形不变性，我们研究Casimir力在三临界点所施加的长程涨落的序参数场。特别注意的情况下，对称性被打破的边界条件（非凡的过渡）。除了平行板的配置，我们还讨论了两个单独的球和一个单一的球附近的平面壁，这可能是一个模型的胶体粒子浸没在流体中的几何形状。在具体的情况下，三元混合物的定量比较与临界卡西米尔和范德华力表明，特别是与临界破坏边界，三临界卡西米尔力是相当强的临界之一，并占主导地位的竞争也范德华力。

两个膜状夹杂间类Casimir力的涨落

Fluctuations of the Casimir-like force between two membrane inclusions

虽然卡西米尔力与它们的涨落是分不开的，但人们对软物质系统中的这些涨落知之甚少。我们使用膜应力张量来研究膜介导的类Casimir力的波动。这种方法使我们能够恢复两个夹杂物之间的Casimir力，并计算其方差。我们证明了Casimir力是由它的涨落决定的。此外，当夹杂物之间的距离d从无穷大减小时，卡西米尔力的方差减小为-1/d^2。这种距离依赖性与卡西米尔力本身有着共同的物理起源。