Perspective on the quantum vacuum in matter

作者：Andrey Baydin, Hanyu Zhu, Motoaki Bamba, Kaden R. A. Hazzard, Junichiro Kono · 发表于：Optical Materials Express · 年份：2025 · DOI：10.1364/ome.569339 · 被引用次数：8 · 研究领域：Quantum Mechanics and Applications、Cold Atom Physics and Bose-Einstein Condensates、Quantum and Classical Electrodynamics

An intriguing consequence of quantum field theory is that a vacuum is not an empty space; it is full of fluctuating electromagnetic fields, or virtual photons, corresponding to their zero-point energy, even though the average number of photons is zero. These short-lived vacuum fluctuations are behind some of the most fascinating physical processes in the universe, including spontaneous emission, the Lamb shift, and the Casimir force. Recent theories and experiments indicate that the properties of materials placed in photonic cavities may be altered, even in the complete absence of any external fields, through interaction with the fluctuating vacuum electromagnetic fields. Judicious engineering of the quantum vacuum surrounding the matter inside a cavity can lead to significant and nonintuitive modifications of electronic and vibrational states, producing a “vacuum-dressed” material. These exciting new ideas have stimulated discussions regarding the fundamental physics of vacuum–matter interactions and also broadened the scope of potential applications using zero-point fluctuations to engineer materials. This Perspective will first discuss recent experimental and theoretical developments on vacuum-modified condensed matter systems, which usually require the realization of the so-called ultrastrong light–matter coupling regime. Then, we will overview some of the most promising cavity designs for enhancing vacuum electromagnetic fields in materials with various energy scales. Fi...