Quantum Kinetics for Quantum Friction: a Materials Perspective

两个距离很近但不接触的物体之间的相对位移会产生摩擦，这是一种普遍存在的现象，导致能量耗散，这往往会导致设备的效率和可靠性降低。这种摩擦的来源是物体表面的量子真空波动，称为量子摩擦。这个项目的重点是量子摩擦，其总体范围是推进对源于量子真空的时间依赖过程的基本理解。目标是发展一种理论，可以为超灵敏力和扭矩实验提供见解和指导，这对于利用量子真空的新途径很重要。该项目通过寻找增强或抑制量子摩擦的有效控制“旋钮”，促进对新材料及其光学响应特性的深入研究。培训学生和博士后是这项研究的重要组成部分，这是一个很好的平台，为新的专业人员在一个协作团队中研究前沿问题。创造一个让高中生参与的环境，这也是这项研究的设想，有望吸引有动力的年轻人帮助他们走上科学或工程的大学道路。本研究旨在开发一种统一的动力学方法，该方法在同等基础上考虑了相对运动物体的时间、速度、距离分离和光学响应特性。该方法依赖于投影密度算子的概念，通过几何相位、跃迁速率、退相干和脱相进入量子摩擦现象。先进的理论方法也将被开发来计算材料的光学响应，以纳入量子摩擦的动力学描述。该项目旨在扩大在零温度和有限温度下与真空电磁波动相关的非幺正耗散过程中贝里类几何相位的意义。深入研究拓扑和其他材料的光学响应，这对于揭示新的等离子体模式-原子结构关系尤其重要，以揭示量子摩擦控制的实际“旋钮”。除了力之外，量子摩擦特征将被识别为特征，例如几何相位和转变速率，以扩大和多样化未来测量这种难以捉摸的效应的实验努力。该研究还将为超灵敏力和扭矩检测以及磁共振力显微镜检测单自旋等实验研究提供新的见解。这种精确的实验及其正确的解释对于利用真空达到有用的目的具有重大意义。该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。

The relative displacement between two objects in close proximity, but not touching, gives rise to friction, a ubiquitous phenomenon resulting in energy dissipation, which often leads to reduced efficiency and reliability of devices. The source of this friction is quantum vacuum fluctuations on the surfaces of the objects, referred to as quantum friction. This project focuses on quantum friction, and its general scope is to advance the fundamental understanding of time-dependent processes stemming from the quantum vacuum. The goal is to develop a theory that can give insights and guidance into ultrasensitive force and torque experiments that are important for new pathways for harnessing the quantum vacuum. The project promotes in-depth studies of novel materials and their optical response properties by finding effective control “knobs” for enhancing or inhibiting quantum friction. Training students and postdocs is an important part of this research, which is an excellent platform for new professionals working on cutting edge problems in a collaborative team. Creating an environment to involve high school students, which is also envisioned for this research, promises to attract motivated young people to help with their college paths in science or engineering.This research aims at developing a unified kinetic approach that takes into account on equal footing time, velocity, distance separation, and optical response properties of the objects that are in relative motion. The method relies on projection density operator concepts through which geometric phases, transition rates, decoherence, and dephasing enter into quantum friction phenomena. Advanced theoretical methods will also be developed to calculate the optical response of materials to be incorporated in the kinetic description of quantum friction. The project aims to broaden the meaning of Berry-like geometric phases in nonunitary dissipative processes associated with vacuum electromagnetic fluctuations at zero and finite temperatures. In-depth studies of the optical response of topological and other materials, which is important especially for uncovering novel plasmon modes-atomic structures relations, will be carried out in order to uncover practical “knobs” for quantum friction control. In addition to the force, quantum friction signatures will be identified in characteristics, such as geometric phases and transition rates, to expand and diversify future experimental endeavors in measuring this elusive effect. This research will also give new insights for experimental studies concerning ultrasensitive force and torque detection as well as detection of single spins by magnetic resonance force microscopy among others. Such precise experiments and their proper interpretation are of great relevance for harnessing the empty vacuum for useful purposes.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.