Abstract: In this talk, I discuss our recent research findings in nano-optics, electromagnetics and acoustics, showing how suitably tailored meta-atoms and arrays of them enable new phenomena to manipulate light and sound at the nanoscale. I discuss venues to largely control the optical response of materials through geometrical rotations, and to break Lorentz reciprocity and realize isolation without the need of a magnetic bias based on broken time-reversal symmetry induced by mechanical motion, spatio-temporal modulation and/or nonlinearities. I also discuss how broken symmetries in space and space-time provide the opportunity to induce topological order in metamaterials. Another class of metamaterials based on broken symmetries are parity-time symmetric media, which are asymmetric in space, but symmetric upon parity and time inversion, and can enhance the exotic response of metamaterials beyond the limitations of passive systems. In the talk, I will discuss the impact of these concepts from basic science to technology, from classical waves to quantum phenomena.

Bio: Andrea Alù is the Founding Director and Einstein Professor at the Photonics Initiative, CUNY Advanced Science Research Center. He received his Laurea (2001) and PhD (2007) from the University of Roma Tre, Italy.