Quantum Kinetics for Quantum Friction: a Materials Perspective

University Of South Florida, Tampa FL

Investigators

Abstract

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.