State Key Laboratory of Terahertz and Millimeter Waves
(City University of Hong Kong)
Seminar on
Some new forms of magnetic photonic crystals
Professor Che Ting Chan
Daniel C K Yu Professor of Science,
Chair Professor of Physics,
Director of Research Office
The Hong Kong University of Science and Technology
Date : 29 November 2024 (Friday)
Time : 10:00 am – 11:00 am
Venue : Room 6-208, 6/F, Lau Ming Wai Academic Building
Abstract
In this talk, we will discuss our group's progress on the topological aspects of magnetic photonic crystals. We introduce the concept of photonic alloys as non-periodic topological materials. These new disordered materials show that combining non-magnetized and magnetized components in a 2D photonic crystal can lead to non-trivial topology and edge states characterized by the winding of the reflection phase. Notably, we observe non-reciprocal chiral edge states due to a local breakdown of time-reversal symmetry. Additionally, we present gyromagnetic the notion of double-zero-index metamaterials (GDZIM), which have zero scalar permittivity and a unique magnetic property with a zero determinant. GDZIMs are excellent for generating complex optical pulses, known as spatiotemporal vortex pulses, linked to the bulk Dirac point. Our key discovery is that the stability of GDZIMs stems from a unique relationship at the topological transition point, revealing connections between zero-refractive-index photonics, topological photonics, and singular optics. We will also discuss the possibility of achieving robust waveguide states using heterostructures comprising of magnetic photonic crystals.
Biography
Professor Che Ting Chan received his BSc degree from the HKU in 1980 and his PhD degree from the UC Berkeley in 1985. He is the Daniel C K Yu Professor of Science, Chair Professor of Physics, and the Director of Research Office of HKUST. He has been elected a Fellow of the American Physical Society and the Physical Society of Hong Kong and a member of the Hong Kong Academy of Sciences.
*** ALL ARE WELCOME ***
Enquiries:
Professor Chi Hou Chan, State Key Laboratory of Terahertz and Millimeter Waves
Tel.: (852) 3442 9360 Fax: (852) 3442 0353 Email: eechic@cityu.edu.hk
