Recently, Dianyuan Fan’s research team of International Collaborative Laboratory of 2D Materials for Optoelectronic Science and Technology of Ministry of Education in our University observed an ideal Weyl system in experiment through a photonic platform in collaboration with Professor Shuang Zhang from University of Birmingham.
They published an original research article entitled “Ideal Weyl points and helicoid surface states in artificial photonic crystal structures” in Science.
Qinghua Guo, a postdoctoral at Shenzhen University, is the first co-author of the article. Associate Professor Yuanjiang Xiang is the co-author of the paper. University of Birmingham, Shenzhen University, University of Exeter and the Institute of Physics of the Chinese Academy of Sciences contributed equally to this work.
Weyl points are the crossings of linearly dispersing energy bands of three-dimensional crystals, providing the opportunity to explore a variety of intriguing phenomena such as topologically protected surface states and chiral anomalies. However, the lack of an ideal Weyl system in which the Weyl points all exist at the same energy and are separated from any other bands poses a serious limitation to the further development of Weyl physics and potential applications. By experimentally characterizing a microwave photonic crystal of saddle-shaped metallic coils (Figure 1), the group observed ideal Weyl points that are related to each other through symmetry operations. Topological surface states exhibiting helicoidal structure have also been demonstrated (Figure 2). Their system provides a photonic platform for exploring ideal Weyl systems and developing possible topological devices.
The work was funded by the Natural Science Foundation of China.