In 2021, Dr. Chen FANG (Institute of Physics, Chinese Academy of Sciences) together with Masashi OTANI (KEK)

and Yangping SHEN (Nuclear Physics, China Institute of Atomic Energy) was awarded C. N. Yang Award 2021.

See the link (http://www.aapps.org/myboard/list_blog.php?Page=1&Board=chen_ning_yang) for more information.

Here is the citation:

"For his founding contribution in coining higher-order topological insulators and in completing a fast-diagnosis scheme for topological materials."

Dr. Fang has played a key role in solving two important problems in this field, known as “diagnosis” and “classification”, with the key concept of “topological invariant”, a global quantum number that is used to distinguish topological materials from non-topological ones and to classify various types of topological materials. Note that the types and forms of all topological invariants depend only on two factors: symmetry and dimensionality. Identifying all invariants for a given dimension and symmetry group of interest is, therefore, an important “classification problem” for theorists. Dr. Fang’s recent works in Phys. Rev. Lett. 119, 246402 (2017) and Nature Communications 9, 3530 (2018), for the first time, identify four new Z2 topological invariants in 3D for the following spatial symmetries: rotation, screw rotation, roto-reflection, and inversion. He then used a theoretical tool, “layer construction”, to solve the classification problem.