Title: 3D Topological Photonics: 3D Chern Photonic Insulators and Electromagnetic Axions
When: Monday, January 13, 2025, 12:00
Place: Department of Theoretical Condensed Matter Physics, Faculty of Sciences, Module 5, Seminar Room (5th Floor)
Speaker: Aitzol García-Etxarri, * Donostia International Physics Center, 20018 Donostia-San Sebastián, Spain, ** IKERBASQUE, Basque Foundation for Science, Maria Diaz de Haro 3, 48013 Bilbao, Spain
Inspired by the discoveries of topological phenomenain solid state systems, the study of topology in the propagation of light in photonic crystals has been the subject of much recent attention. Among all topological states of matter, time-reversal symmetry (TRS) broken topological materials, such as Chern insulators have been a particular focus due to their topologically protected unidirectional edge states with non-reciprocal propagation properties. In these systems, scattering processes from one boundary state into another are strongly suppressed, due to decoupling of counter-propagating 1D chiral edge channels. In this contribution, we will firstly introduce a general strategy to design 3D Chern insulating (3D CI) cubic photonic crystals in a weakly TRS broken environment with orientable and arbitrarily large Chern vectors. The resulting 3D Chern insulator, is a photonic topological phase which is forbidden in solid state materials. Secondly, we will show how these designs can be used to build photonic axion insulators. Such a 3D topological photonic crystal exhibits extraordinary properties such as half-quantized surface effects and unidirectional chiral hinge states that propagate exclusively along the edges. These chiral hinge states form intricate networks that enable light to travel without loss or interference, even when obstacles are present. This breakthrough offers a deeper understanding of exotic particles and paves the way for practical applications in quantum computing, advanced sensors or in the development of axion-like particle detectors such as axion dark matter particles.
