Advances in Casimir-Polder Interactions between Atoms and Substrates

原子与底物卡西米尔-波尔德相互作用的研究进展

• 批准号: 2008417
• 负责人: Kimball Milton
• 金额: $ 24万
• 依托单位: University of Oklahoma Norman Campus
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2008417&HistoricalAwards=false
• 关键词: Advances; Casimir; Polder; Interactions; between

The quantum vacuum is a busy place, with particles popping into and out of existence for short periods of time. This activity gives rise to amazing phenomena, such as the attractive force between closely-spaced uncharged conducting plates, or between neutral atoms, discovered by Casimir more than 70 years ago. A beginning is being made to see how to exploit these Casimir forces in practical devices and nanomachinery. By changing the properties of the objects that interact, and the environment in which they are immersed, the forces can be repulsive rather than attractive. When the objects and atoms are in motion, quantum frictional forces arise between atoms and surfaces even when they are not in contact. This project advances the progress of science and promotes the education of a diverse group of students and researchers. This interdisciplinary work has significant impacts in biology, chemistry, atomic and nuclear physics, and is even finding applications in planetary science.Specific topics to be considered include: (1) Negative Casimir entropies. It is now well known that the interaction entropy between atoms, or between atoms and metallic surfaces, for example, are often negative. Although it was suggested that the positive self-entropies of the atoms themselves would cancel this effect, we have now discovered that this is in general not the case, and that self interactions typically lead to a region of negative entropy. (2) Quantum vacuum forces between atoms and surfaces in inhomogeneous media. Nearly all work on Casimir forces between bodies assumes they are separated by vacuum, or by a homogeneous dielectric medium. But if they they are separated by a spatially varying medium, divergences appear which are not well understood. The group has made some preliminary proposals as to how to extract meaningful interaction energies, but the general situation will require much more work. (3) Repulsive Casimir forces and nonmonotonic torques. Casimir forces can turn repulsive, and not merely with exotic combinations of materials. This is not unrelated to the negative entropies seen ubiquitously, and reflects the nonmonotonicity of the free energy. With anisotropic materials, Casimir torques can undergo sign changes with the distances between atoms and surfaces. Real-world applications to such long-standing problems such as the freezing of ice, and the interaction of greenhouse gases with substrates are being explored. (4) Casimir friction. When an atom or a dielectric plate is moved parallel to nearby plate, a frictional force is experienced due to the interaction with the fluctuations in the electromagnetic vacuum. This requires understanding nonequilibrium dissipative effects. Systematic ways of treating such phenomena are being developed, with the intent of proposing accessible experimental signatures.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

量子真空是一个繁忙的地方，粒子在短时间内突然进入和消失。这种活动产生了令人惊讶的现象，例如卡西米尔70多年前发现的紧密排列的不带电荷的导电板之间的吸引力，或者中性原子之间的吸引力。人们开始研究如何在实际设备和纳米机械中利用这些卡西米尔力。通过改变相互作用的物体的属性以及它们所处的环境，这些力可能是排斥的，而不是吸引的。当物体和原子运动时，即使原子和表面没有接触，原子和表面之间也会产生量子摩擦力。这个项目推动了科学的进步，促进了对不同群体的学生和研究人员的教育。这项交叉学科的工作在生物、化学、原子和核物理方面有重大影响，甚至在行星科学中也有应用。需要考虑的具体课题包括：(1)负卡西米尔熵。现在众所周知，原子之间的相互作用熵，或者原子与金属表面之间的相互作用熵，通常是负的。虽然有人认为原子本身的正自熵会抵消这一效应，但我们现在发现，通常情况并非如此，而且自相互作用通常会导致负熵区域。(2)非均匀介质中原子与表面之间的量子真空力。几乎所有关于物体之间的卡西米尔力的研究都假定它们是由真空或均匀的介质介质分开的。但如果它们被空间变化的介质隔开，就会出现人们不太了解的分歧。该小组已经就如何提取有意义的相互作用能量提出了一些初步建议，但总体情况需要做更多的工作。(3)排斥Casimir力和非单调扭矩。卡西米尔的力量可能会变得令人厌恶，而且不仅仅是因为奇异的材料组合。这与无处不在的负熵不无关系，反映了自由能的非单调性。对于各向异性材料，Casimir扭矩可以随着原子与表面之间的距离发生符号变化。人们正在探索在现实世界中应用于诸如冰冻、温室气体与基质相互作用等长期存在的问题。(4)卡西米尔摩擦。当原子或介质板平行于邻近的板运动时，由于与电磁真空中的涨落相互作用而产生摩擦力。这需要了解非平衡耗散效应。这一奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Casimir self-entropy of nanoparticles with classical polarizabilities: Electromagnetic field fluctuations

具有经典极化率的纳米颗粒的卡西米尔自熵：电磁场涨落

• DOI: 10.1103/physrevd.106.036002
• 发表时间: 2022
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Li, Yang;Milton, Kimball A.;Parashar, Prachi;Kennedy, Gerard;Pourtolami, Nima;Guo, Xin
• 通讯作者: Guo, Xin

Quantum friction in the presence of a perfectly conducting plate

存在完美导电板时的量子摩擦

• DOI: 10.1103/physreva.107.062812
• 发表时间: 2023
• 期刊: Physical Review A
• 影响因子: 2.9
• 作者: Guo, Xin;Milton, Kimball A.;Kennedy, Gerard;Pourtolami, Nima
• 通讯作者: Pourtolami, Nima

Origin of anomalously stabilizing ice layers on methane gas hydrates near rock surface

岩石表面附近甲烷气体水合物异常稳定冰层的起源

• DOI: 10.1039/d2cp04883c
• 发表时间: 2023
• 期刊: Physical Chemistry Chemical Physics
• 影响因子: 3.3
• 作者: Li, Yang;Corkery, Robert W.;Carretero-Palacios, Sol;Berland, Kristian;Esteso, Victoria;Fiedler, Johannes;Milton, Kimball A.;Brevik, Iver;Boström, Mathias
• 通讯作者: Boström, Mathias

Premelting and formation of ice due to Casimir-Lifshitz interactions: Impact of improved parameterization for materials

卡西米尔-利夫什茨相互作用导致冰的预熔化和形成：改进材料参数化的影响

• DOI: 10.1103/physrevb.105.014203
• 发表时间: 2022
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Li, Yang;Milton, Kimball A.;Brevik, Iver;Malyi, Oleksandr I.;Thiyam, Priyadarshini;Persson, Clas;Parsons, Drew F.;Boström, Mathias
• 通讯作者: Boström, Mathias

Energetics of quantum vacuum friction. II. Dipole fluctuations and field fluctuations

量子真空摩擦的能量学。

• DOI: 10.1103/physrevd.106.016008
• 发表时间: 2022
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Guo, Xin;Milton, Kimball A.;Kennedy, Gerard;McNulty, William P.;Pourtolami, Nima;Li, Yang
• 通讯作者: Li, Yang