Title: Unravelling the topological phase of light and matter: Physics and Device applications

Speaker: Dr. Abhishek Kumar, Jawaharlal Nehru Center for Advanced Scientific Research, Bangalore

Abstract: For many decades, physicists have used the concept of symmetry breaking to distinguish between different phases of matter. However, recent advancements have shown that topology offers a universal method for classifying matter based on topological phases. Their hallmark feature is the appearance of edge states which are robust to backscattering at the interface between two materials of different topological phases. Recently, the concept of topology has been extended to photonics, leading to the field of topological photonics, which aims to achieve robust and dissipation less transport of photon. The flexibility to implement engineered Hamiltonians has made topological photonics a unique platform to study topological phenomena and promises exceptional applications in integrated photonics.

In this talk, I will discuss how the topological phases of light in valley photonic crystal (VPC) enable unique functionalities in photonic devices. Leveraging the robustness of valley edge states, I have developed a terahertz topological photonic integrated platform, vital for realizing next generation 6G communication, high-speed on chip interconnects and exploring topological light-matter interactions. Additionally, I will present the underlying physics behind the slow-light effect in VPC and their active control. The new paradigm introduced by the topological phase of light holds the potential to revolutionize various fields of natural science, including condensed matter physics, quantum technologies and photonics.