Published on 14 Mar 2024

When Chirality Meets Topology in Materials by Nanyang Assistant Prof Chang Guoqing

IAS Discovery Science Seminar Jointly Organised with the Graduate Students’ Clubs

Nanyang Assistant Prof Chang Guoqing gave an enlightening talk "When Chirality Meets Topology in Materials" on 6 March 2024 at SPMS LT4. The Discovery Science Seminar was jointly organised by IAS NTU and SPMS, EEE, and MSE Graduate Student Clubs.

Dr Chang has embarked on an impressive academic journey, earning his PhD from the National University of Singapore in 2017. Following this, he engaged in research at Princeton University before taking up a position as an Assistant Professor at NTU in 2020. Dr Chang is a highly esteemed physicist, renowned for his groundbreaking contributions to the field. Since 2019, he has consistently been recognised as one of the world's most cited researchers in physics. His exceptional work was further celebrated in 2023 with the prestigious Singapore Young Scientist Award and a well-deserved spot on MIT Technology Review's "Innovators Under 35" list for the Asia Pacific region.

Dr Chang explaining the topological chirality and Weyl materials to the audience.

Dr Chang delved into the fascinating realm of chirality within a specific type of crystal known as chiral crystals. A highlight of the lecture was gaining a deeper understanding of chirality and its applications in electronic systems, particularly in kagome lattices and photogalvanics. The detailed explanations provided insightful information, allowing us to learn new things and gain exposure to a completely different field of study.

Furthermore, Dr Chang explained that these crystals have a unique internal structure that affects how electrons move around inside them. It's like a special code, called a Chern number, that scientists use to characterise this phenomenon.

To enhance clarity, Dr Chang focused on a group of crystals within the RhSi family, which showcase intriguing quantum behaviours, emphasising the remarkable potential of these "handed" materials. The talk concluded by exploring the complex relationship between chirality and how electrons interact in these crystals. 

(Top) Curious participants posing insightful questions; (Bottom) Group photo of the participants.

Overall, Dr Chang's talk was eye-opening. The entirety of the lecture delved into the fascinating world of Weyl materials, providing a comprehensive overview that was both informative and thought-provoking. He was really passionate about it, which left everyone wanting to know more about the hidden magic inside these of these materials. 

Written by Kivanc Saglik | School of Materials Science and Engineering Graduate Students' Club

Watch the video recording

"The lecture extensivity covered the concept of chirality with great depth and length, thanks to Dr Chang for this enlightening session." - Adira Mohitha (PhD student, SPMS)

"Gained new knowledge of chirality." -Putu Eka Dharma Putra (PhD student, MSE)

"Learned concept of chirality and the application in electronic systems." -Lei Yusheng (PhD student, CCEB)