报告题目：Photonic Axion Insulator

报 告 人：Baile Zhang，School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore

报告时间：2024年10月17日10:00

报告地点：理科楼C302

内容摘要：Axions are hypothetical particles originally proposed to solve the strong charge-parity (CP) problem in the Standard Model and later predicted to constitute the elusive dark matter. While still not observed as elementary particles, axions can arise as quasiparticles in three-dimensional topological crystals known as axion insulators. The bulk of the crystal is characterized by a quantized axion field angle θ = π, which induces half-quantized Chern numbers across all surfaces. Previous axion insulators were predominantly implemented either on a two-dimensional interface, or quasi-2D “thin film” geometries. Here, we will discuss how to realize a three-dimensional axion insulator in photonic crystals. This line of research follows our previous works on three-dimensional photonic topological insulators with and without magnetic materials.  

报告人简介：Baile Zhang is a professor of physics in the School of Physical and Mathematical Sciences at Nanyang Technological University (NTU), Singapore. He obtained his PhD in electrical engineering from the Massachusetts Institute of Technology (MIT) in 2009, following his BS degree in 2003 and MS degree in 2006 from Tsinghua University. After completing a two-year postdoc at the Singapore-MIT Alliance for Research and Technology Centre, he joined NTU in 2011 as an assistant professor. He was subsequently promoted to associate professor in 2017 and then to a full professor in 2021. He received the MIT Technology Review TR35 Award (Global) in 2012. In 2020, he was honoured with the Singapore President’s Science Award together with two other NTU colleagues. His research interests include waves in complex media, metamaterials, photonic and phononic crystals, and acoustics.