Topological insulators are very special materials which behave as insulators in their interior, but that can support conducting states on their surface. These “surface states” are symmetry protected, meaning that, defects in the material cannot destroy them easily. On top of that, these topological edge states are generally protected against backscattering. This last feature implies that if energy (or information) is flowing in one particular direction through the surface of a topological insulator, it will continue flowing in that particular path even if it finds obstacles on its way. The study of the exotic properties of these novel materials is an incredibly interesting area of research in basic science and could facilitate fantastic engineering applications.

Topological states of matter were first discovered in the field of solid-state physics but recent contributions are proving their existence in diverse physical platforms. To mention a few, topological surface states have been recently identified in the fields of optics, acoustics and in excitonic and polaritonic materials. Most of these cross-disciplinary designs have been directly inherited from concepts previously discovered in electronic materials. Nevertheless, these different physical mechanisms, should lead to distinct effects with interesting properties of their own. Unfortunately, those assets will remain hindered if the research on topological effects in these fields continues to be exclusively based on analogies with solid-state systems.

In this line of research, our group focuses on the exploration of emergent topological effects in optical systems. Our aim is to exploit the exotic properties of topological photonic materials to unveil novel ways of manipulating the propagation of light which could facilitate innovative light-matter interactions at the nanoscale.