Non-reciprocal energy transfer through the quantum vacuum fluctuations

Quantum mechanics predicts random fluctuations of electromagnetic fields in vacuum which leads to the well-known Casimir force between macroscopic bodies. Efforts have been made to create various Casimir-based devices. However, the regulation of phonon transfer and dynamics between two closing surfaces by quantum vacuum fluctuations is still an unexplored frontier. In this talk, I will present the first experimental demonstration of quantum vacuum mediated non-reciprocal energy transfer between two micromechanical oscillations. The strong coupling is realized by modulating the Casimir interaction parametrically at nanoscale. We design and engineer the system’s spectrum to include an exceptional point in the parameter space and observe the topological structure near the exceptional point. By dynamically changing the parameters near the exceptional point, non-reciprocal energy transfer with high contrast is realized. In this way, we develop a flexible and robust method to regulate quantum fluctuations and build functional Casimir devices.