Abstract
Metamaterials—composed of sub-wavelength structures arranged periodically—have garnered significant attention due to their unique interactions with electromagnetic waves, leading to enhanced antenna performance, perfect absorption, and invisibility effects. Most studies have focused on metamaterials with time reversal symmetry, whose application is limited in reciprocal devices, such as clocking and negative index. This seminar introduces the design and application of metamaterials with broken time-reversal symmetry, specifically Tellegen and artificial moving metamaterials, which exhibit real value of cross-coupling between electric and magnetic fields. A pure Tellegen response is achieved through the combination of gyromagnetic materials and split-ring resonators. This response is characterized by an exceptionally strong Kerr rotation, surpassing that of natural materials by several orders of magnitude. Moreover, the artificial moving coupling is realized with an effective velocity of approximately 0.4c by integrating gyromagnetic materials with chiral structures. Experimental observations revealed that when waves impinge on the slabs from opposite directions, the amplitude of transmission remains identical, imparting merely a phase difference, while the reflection properties remain unchanged. Moreover, we also investigate potential applications by the new metamaterials.
Anyone interested is welcome to attend.