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Abstract:
For decades, lasers have been the cornerstone for manipulating solid-state materials, using intense light fields to control their electronic, lattice, and spin dynamics. Yet, this reliance on external light sources introduces inherent challenges, including transient effects, heating, and a continuous need for energy input. In contrast, a new paradigm is emerging: cavity materials engineering. By placing materials within optical or terahertz cavities, we can leverage the strong confinement of electromagnetic fields, where even the vacuum fluctuations of these fields can fundamentally alter material behavior. This approach allows us to influence key properties—such as magnetotransport, metal–insulator transitions, and superconductivity— without any external light input.

This talk will explore the latest advancements in quantum electrodynamical density functional theory (QEDFT), a powerful ab initio framework that integrates the electron and photon modes on an equal footing, providing a deeper understanding of light-matter coupling in cavity systems. I will present case studies demonstrating how fine-tuning cavity mode structures can modify the electronic band structure, phonon dynamics, and superconducting properties of materials, all driven by photon quantum fluctuations. The presentation will conclude with a discussion on how QEDFT can be expanded to study complex materials systems, offering new possibilities for designing stable, cavity-engineered materials at equilibrium, and setting the stage for future breakthroughs in materials science.