Obukhov S P, Semenov A N
Department of Physics, University of Florida, Gainesville, FL, USA
Phys Rev Lett. 2005 Jul 15;95(3):038305. doi: 10.1103/PhysRevLett.95.038305.
It is well known that small neutral particles normally tend to aggregate due to the van der Waals forces. We discover a new universal long-range interaction between solid objects in polymer media that is directly opposite the van der Waals attraction. The new force could reverse the sign of the net interaction, possibly leading to the net repulsion. This universal repulsion comes from the subtracted soft fluctuation modes, which are not present in the real polymer system, but rather are in its ideal counterpart. The predicted effect has a deep relation to the classical Casimir interactions, providing an unusual example of fluctuation-induced repulsion instead of normal attraction. That is why it is referred to as the anti-Casimir effect. We also find that the correlation function of monomer units in a concentrated solution of infinite polymer chains follows a power-law rather than an exponential decay at large distances.
众所周知，由于范德华力，小的中性粒子通常倾向于聚集。我们发现了聚合物介质中固体物体之间一种新的普遍的长程相互作用，它与范德华引力直接相反。这种新力可能会使净相互作用的符号反转，从而可能导致净排斥。这种普遍的排斥力来自于被减去的软波动模式，这些模式在实际聚合物系统中不存在，而是存在于其理想对应物中。预测的效应与经典卡西米尔相互作用有深刻的关系，提供了一个由波动引起排斥而非正常吸引的不寻常例子。这就是为什么它被称为反卡西米尔效应。我们还发现，在无限长聚合物链的浓溶液中，单体单元的相关函数在大距离处遵循幂律而非指数衰减。
